technical committee on single burner boilers nfpa 85 … · bcs-sbb joseph e. fehr principal sega,...

TECHNICAL COMMITTEE ON SINGLE BURNER BOILERS

NFPA 85 First Draft Meeting Agenda

February 10, 2017 8:00 AM - 5:00 PM MT Embassy Suites by Hilton Phoenix-Tempe, Tempe, AZ

1. Call to Order. Peter Willse, Chair

2. Introductions.

3. Approval of Meeting Minutes from November 16, 2016.

4. Staff Updates. Laura Moreno, NFPA Staff

Committee membership update. (Attachment A)

Fall 2018 revision cycle schedule. (Attachment B)

Overview of NFPA Process

5. Review of Public Inputs: NFPA 85 Chapter 5 (Attachment C)

6. Review of Fundamentals Technical Committee actions (Attachment D). The committee members are asked to review the actions and bring forward any items warranting further discussion.

7. Task Group Reports.

Chapter 5 Reorganization. John Eibl, Task Group Chair

8. New Business.

9. Next Meeting.

10. Adjourn.

NFPA 85 (BCS-SBB) Technical Committee on Single Burner Boilers First Draft Meeting February 10, 2017 - Tempe, AZ

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Attachment A: Committee Roster


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Address List No PhoneSingle Burner Boilers BCS-SBB

Boiler Combustion System Hazards

Laura E. Moreno01/25/2017

BCS-SBB

Peter J. Willse

ChairXL Catlin Property Risk Engineering/GAP100 Constitution Plaza, 12th FloorHartford, CT 06103Alternate: James E. Franks

I 1/1/1989BCS-SBB

Ronald C. Adcock

PrincipalMarsh Risk Consulting2325 East Camelback Road, Suite 600Phoenix, AZ 85016

I 07/29/2013

BCS-SBB

Denise Beach

PrincipalFM Global1151 Boston-Providence TurnpikePO Box 9102Norwood, MA 02062-9102Alternate: Michael McArdle

I 08/17/2015BCS-SBB

David Bohling

PrincipalJohn Zink Company LLC2151 River Plaza Drive, Suite 200Sacramento, CA 95833Alternate: Octavio Serrano

M 03/07/2013

BCS-SBB

Jeff M. Breidenbach

PrincipalLiberty Mutual Commercial Markets, Property4503 Winchester RoadLouisville, KY 40207Alternate: Mark F. Mooney

I 8/9/2011BCS-SBB

David Paul Cannon

PrincipalHurst Technologies13514 Lakeside TerraceHouston, TX 77044

SE 3/1/2011

BCS-SBB

Kevin J. Carlisle

PrincipalKarl Dungs, Inc.3890 Pheasant Ridge Drive, NEBlaine, MN 55449

M 03/03/2014BCS-SBB

John T. Connor

PrincipalBurns & McDonnell Engineering Company9400 Ward ParkwayPO Box 419173Kansas City, MO 64141-6173Alternate: Enrique Jorge Jimenez

SE 3/21/2006

BCS-SBB

Dale E. Dressel

PrincipalSolutia, a subsidiary of Eastman Chemical Company575 Maryville Centre Drive, 2SPO Box 66760St. Louis, MO 63166-6760

U 4/26/1988BCS-SBB

Fedja Drndarevic

PrincipalTechnical Standards and Safety Authority345 Carlingview DriveToronto, ON M9W 6N9 Canada

E 10/18/2011

BCS-SBB

John J. Eibl

PrincipalThe Chemours Company Inc.412 Fontaine DriveFranklin, TN 37064-0715

U 04/01/1994BCS-SBB

Joseph E. Fehr

PrincipalSega, Inc.16041 FosterPO Box 1000Overland Park, KS 66085

SE 3/4/2009

BCS-SBB

Richard A. Gallagher

PrincipalZurich Services Corporation5124 New Kent RoadWilmington, DE 19808-2706

I 03/07/2013

1NFPA 85 (BCS-SBB) Technical Committee on Single Burner Boilers First Draft Meeting February 10, 2017 - Tempe, AZ

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BCS-SBB

Ted Jablkowski

PrincipalFives North American Combustion, Inc.287 Boston Post RoadPO Box 160East Lyme, CT 06333Alternate: William M. Rucki

M 3/21/2006BCS-SBB

Patrick Jennings

PrincipalHartford Steam BoilerOne State StreetHartford, CT 06102

I 07/29/2013

BCS-SBB

John F. Kane

PrincipalThe DuPont Company, Inc.6324 Fairview Road, Suite 200Charlotte, NC 28210-3271

U 12/08/2015BCS-SBB

Raymond Labore

PrincipalUTC/Fireye Inc.3 Manchester RoadDerry, NH 03038-3031

M 08/11/2014

BCS-SBB

John D. Martens

PrincipalExponent, Inc.525 West Monroe StreetSuite 1050Chicago, IL 60661-3644Alternate: Mark T. Fecke

SE 08/17/2015BCS-SBB

W. Scott Matz

PrincipalSchneider Electric/Invensys10900 Equity DriveHouston, TX 77041

M 10/27/2009

BCS-SBB

Anthony Joseph Mayle

PrincipalBabcock & Wilcox20 South Van Buren AvenueBarberton, OH 44203Alternate: Brent Diley

M 11/30/2016BCS-SBB

Gary Persichini

PrincipalVictory Energy Operations LLC10701 East 126th Street NorthCollinsville, OK 74021

M 08/03/2016

BCS-SBB

Peter S. Pinto

PrincipalSCC, Inc.1250 Lunt AvenueElk Grove Village, IL 60007-5618Alternate: Mark Waszczak

M 7/23/2008BCS-SBB

William A. (Andy) Smith

PrincipalAmerican International Group, Inc. (AIG)1200 Abernathy Road NEBuilidng 600, 8th FloorAtlanta, GA 30328

I 08/03/2016

BCS-SBB

Franklin R. Switzer, Jr.

PrincipalS-afe, Inc.85 Denison Parkway E #201Corning, NY 14830-2726

SE 7/16/2003BCS-SBB

Dennis Szabo

PrincipalSzabo Loss Control Incorporated9599 Gillsville RoadMaysville, GA 30558-1721

SE 10/28/2008

BCS-SBB

Scott G. Vickery

PrincipalAscend Performance MaterialsPO Box 711, FM 2917Alvin, TX 77512

U 7/23/2008BCS-SBB

Marc A. Wolff

PrincipalFederal Bureau Of Prisons500 First Street North West, 8th FloorWashington, DC 20534

U 11/30/2016


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BCS-SBB

Donald Zissa

PrincipalSIS-TECH12621 Featherwood, Suite 120Houston, TX 77034-4905

SE 08/17/2015BCS-SBB

Mark V. Urda

Voting AlternateSynergy Systems Inc.1982 Ohio StreetLisle, IL 60532

SE 07/29/2013

BCS-SBB

Brent Diley

AlternateBabcock & Wilcox20 South Van Buren AvenueBarberton, OH 44203Principal: Anthony Joseph Mayle

M 11/30/2016BCS-SBB

Mark T. Fecke

AlternateExponent, Inc.4580 Weaver Parkway, Suite 100Warrenville, IL 60555Principal: John D. Martens

SE 08/17/2015

BCS-SBB

James E. Franks

AlternateGlobal Asset Protection Services, LLC855 Dogwood RoadSomerville, TN 38068Principal: Peter J. Willse

I 08/09/2012BCS-SBB

Enrique Jorge Jimenez

AlternateBurns And Mcdonnell1700 West Loop South, Suite 1500Houston, TX 77027Principal: John T. Connor

SE 11/30/2016

BCS-SBB

Michael McArdle

AlternateFM Global810 Briar LaneCatawissa, MO 63015FM GlobalPrincipal: Denise Beach

I 08/03/2016BCS-SBB

Mark F. Mooney

AlternateLiberty Mutual Insurance Company20 Riverside Road, MS: 03BNWeston, MA 02493-2231Principal: Jeff M. Breidenbach

I 8/9/2011

BCS-SBB

William M. Rucki

AlternateFives North American Combustion, Inc.4455 East 71st StreetCleveland, OH 44105Principal: Ted Jablkowski

M 8/5/2009BCS-SBB

Octavio Serrano

AlternateJohn Zink Company, LLCCoen Division11920 East ApacheTulsa, OK 74116Principal: David Bohling

M 03/07/2013

BCS-SBB

Mark Waszczak

AlternateSCC, Inc.1250 Lunt AvenueElk Grove Village, IL 60007-5618Principal: Peter S. Pinto

M 03/03/2014BCS-SBB

Laura E. Moreno

Staff LiaisonNational Fire Protection Association1 Batterymarch ParkQuincy, MA 02169-7471

01/06/2015


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Attachment B: Fall 2018 Revision Cycle Schedule


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Fall 2018 Revision Cycle

Process Stage Process Step Dates for TCDates for TC

with CC

Public InputStage (First Draft)

Public Input Closing Date* 1/05/2017 1/05/2017

Final Date for TC First Draft Meeting 6/15/2017 3/16/2017

Posting of First Draft and TC Ballot 8/03/2017 4/27/2017

Final date for Receipt of TC First Draft ballot 8/24/2017 5/18/2017

Final date for Receipt of TC First Draft ballot - recirc 8/31/2017 5/25/2017

Posting of First Draft for CC Meeting 6/01/2017

Final date for CC First Draft Meeting 7/13/2017

Posting of First Draft and CC Ballot 8/03/2017

Final date for Receipt of CC First Draft ballot 8/24/2017

Final date for Receipt of CC First Draft ballot - recirc 8/31/2017

Post First Draft Report for Public Comment 9/07/2017 9/07/2017

Comment Stage(Second Draft)

Public Comment Closing Date* 11/16/2017 11/16/2017

Notice Published on Consent Standards (Standards that received no Comments)Note: Date varies and determined via TC ballot.

Appeal Closing Date for Consent Standards (Standards that received no Comments)

Final date for TC Second Draft Meeting 5/17/2018 2/08/2018

Posting of Second Draft and TC Ballot 6/28/2018 3/22/2018

Final date for Receipt of TC Second Draft ballot 7/19/2018 4/12/2018

Final date for receipt of TC Second Draft ballot - recirc 7/26/2018 4/19/2018

Posting of Second Draft for CC Meeting 4/26/2018

Final date for CC Second Draft Meeting 6/07/2018

Posting of Second Draft for CC Ballot 6/28/2018

Final date for Receipt of CC Second Draft ballot 7/19/2018

Final date for Receipt of CC Second Draft ballot - recirc 7/26/2018

Post Second Draft Report for NITMAM Review 8/02/2018 8/02/2018

Tech SessionPreparation (&

Issuance)

Notice of Intent to Make a Motion (NITMAM) Closing Date 8/30/2018 8/30/2018

Posting of Certified Amending Motions (CAMs) and Consent Standards 10/11/2018 10/11/2018

Appeal Closing Date for Consent Standards 10/26/2018 10/26/2018

SC Issuance Date for Consent Standards 11/05/2018 11/05/2018

Tech Session Association Meeting for Standards with CAMs

Appeals andIssuance

Appeal Closing Date for Standards with CAMs

SC Issuance Date for Standards with CAMs

TC = Technical Committee or PanelCC = Correlating Committee

As of 8/30/2016


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Attachment C: NFPA 85 Chapter 5 Public Input Report


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Public Input No. 100-NFPA 85-2016 [ Global Input ]

Replace "practicable" with "practical"

Statement of Problem and Substantiation for Public Input

Something is practicable if it can be done by any means, no matter how impractical. Practical is a word engineers use to allow judgment when making engineering decisions.

Submitter Information Verification

Submitter Full Name: Theodore Lemoff

Organization: TLemoff Engineering

Street Address:

City:

State:

Zip:

Submittal Date: Wed Oct 05 09:52:10 EDT 2016

Copyright Assignment

I, Theodore Lemoff, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights incopyright in this Public Input (including both the Proposed Change and the Statement of Problem and Substantiation). Iunderstand and intend that I acquire no rights, including rights as a joint author, in any publication of the NFPA in which thisPublic Input in this or another similar or derivative form is used. I hereby warrant that I am the author of this Public Input and that Ihave full power and authority to enter into this copyright assignment.

By checking this box I affirm that I am Theodore Lemoff, and I agree to be legally bound by the above Copyright Assignmentand the terms and conditions contained therein. I understand and intend that, by checking this box, I am creating an electronicsignature that will, upon my submission of this form, have the same legal force and effect as a handwritten signature

National Fire Protection Association Report http://submittals.nfpa.org/TerraViewWeb/FormLaunch?id=/TerraView/C...

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Public Input No. 215-NFPA 85-2017 [ Global Input ]

All technical committees should review the proposed changes to the definitions of "trip," "interlock,"and "permissive," as well as the recommendations below:

Draft Definitions and Guidelines developed by the

NFPA 85 Correlating Committee and Fundamentals Committee

Draft definitions for interlock, permissive, and trip.

· Interlock: A function which prevents, limits, stops, or initiates the operation of equipment or a subsequentfunction.

o Annex language: An interlock can consist of a sensing function, a control function, and anoutput or a final control element. The interlock can be accomplished with the use of anycombination of electrical devices, mechanical devices, or logic.

· Permissive: An interlock that functions only to allow initiation of the operation of equipment or asubsequent function

· Trip: An interlock that shuts down equipment when a predefined set of conditions exists.

It was decided that permissive and trip should be subdefinitions under interlock, but they should also appear inalphabetical order with a reference back to the interlock section, similar to what is done for “coal” in 3.3.30.

Recommendations for other Chapters. The following recommendations have been developed for the use of“interlock” and related terms throughout the code:

· “Safety device”, “protective device”, “interlock device” and “safety interlock device” appear to besynonymous. The Fundamentals Committee suggests using "interlocks" or "interlocks and associated devices"as appropriate.

· “Safety function” is similar to the new definition of an interlock. The Fundamentals Committee suggestsusing the term interlock.

· “Master fuel trip device” is not defined in Chapter 3, and is only used in Chapter 7 and its Annex. If this isintentionally different from a master fuel trip relay, it should be defined in Chapter 3. Otherwise, it should bereplaced with “master fuel trip relay”.

· “Safety shutdown” is only used in Chapters 3, 4, and 5, and the Annex to Chapters 5 and 7. Forconsistency throughout the document, the Fundamentals Committee recommends replacement with “trip” or“master fuel trip”, as appropriate. The Fundamentals Committee will be removing the term from Chapters 3 and4.

· “Emergency shutdown” is used in Chapters 4, 6, 7, 8, and 10, and the Annex to Chapters 4, 6, and 7, aswell as Annex B. This appears to be the same as a safety shutdown, so the Committee recommendsreplacement with “trip” or “master fuel trip” as in the comment above. The Fundamentals Committee will beremoving the term from Chapter 4.

· “Abnormal shutdown” is only used twice, both times in Chapter 6. This appears to be synonymous with“trip” and for consistency, that term should be substituted.

· “Interlock system” is used in Chapters 4, 5, 6, 7, 8, and 9. The Fundamentals Committee will be removingthe term from Chapter 4 by replacing it with “interlocks” and recommends replacement in other chapters.


To comply with the recommendations of the Fundamentals TC.


Submitter Full Name: Joseph Fehr

Organization: Sega, Inc.


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Street Address:

City:

State:

Zip:

Submittal Date: Wed Jan 04 15:10:04 EST 2017

Copyright Assignment

I, Joseph Fehr, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright in this PublicInput (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend that I acquire no rights,including rights as a joint author, in any publication of the NFPA in which this Public Input in this or another similar or derivative form is used. Ihereby warrant that I am the author of this Public Input and that I have full power and authority to enter into this copyright assignment.

By checking this box I affirm that I am Joseph Fehr, and I agree to be legally bound by the above Copyright Assignment and the terms andconditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will, upon mysubmission of this form, have the same legal force and effect as a handwritten signature


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Public Input No. 233-NFPA 85-2017 [ New Section after 5.1.3 ]

5.1.4

All safety shutoff valves shall be operationally tested at a minimum once a year.


Some companies are extending scheduled shutdowns beyond 1 year to 2, 3 and in some cases 5 years.


Submitter Full Name: Carlos Santos

Organization: Schneider Electric/Invensys

Street Address:

City:

State:

Zip:


National Fire Protection Association Report http://submittals.nfpa.org/TerraViewWeb/ContentFetcher?commentPara...

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5.1.4.1

At facilities where spare boiler capacity allows, one boiler, at a time, shall be shutdown.






Street Address:

City:

State:

Zip:



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5.1.4.2

At facitlies where more than one fuel is used, one fuel, at a time, shall be shutdown.






Street Address:

City:

State:

Zip:



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5.1.4.3

At facilities where spare boiler capacity or multiple fuels are not an option, on-line testing shall be permittedthrough the use of parallel safety shutoff valves or safety shutoff bypass valves.






Street Address:

City:

State:

Zip:



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Public Input No. 214-NFPA 85-2017 [ Section No. 5.1.3 ]

5.1.3

All safety shutoff valves, safety interlock devices associated with interlocks , valve-proving systems, andflame detection systems shall be listed or approved. A safety shutoff valve proof of closure switch shall bean original design component of the valve or actuator assembly and shall activate only after the valve isfully closed.






Street Address:

City:

State:

Zip:



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Public Input No. 181-NFPA 85-2016 [ Section No. 5.4 ]

Much of Section 5.4 content was proposed to be moved to the Chaper 4 Fundamentals section. The attached Word File identifies the material that was included in a separate proposal sent to theFUN Committee. Depending on what content they either accept or reject, the SBB Committee willneed to review their action and ensure material not accepted by FUN remains in Chapter 5 SBBwith the appropriate formatting.

5.4 Equipment Requirements.

5.4.1* Fuel Supply — Oil.

5.4.1.1

Fuel shall be stored, prepared, and delivered to the oil service connection under anticipated operatingconditions in accordance with the applicable portions of NFPA 31.

5.4.1.2

Operation of the burner shall not be attempted until a continuous fuel supply is ensured.

5.4.1.3

Fuel shall be delivered continuously to the combustion chamber in a finely atomized form that can beignited readily and consumed.

5.4.1.4

All equipment that is associated with pumping, heating, and straining the fuel from storage to the serviceconnection shall be designed, sized, and interconnected so as to provide a fuel supply that meets the boilerdesign requirements over a full range of conditions.

5.4.1.5

Relief valves shall be installed after the pump to prevent overpressure in the system.

5.4.1.6

Fuel being burned shall be delivered to the burner at the temperature and pressure specified by the burnermanufacturer.

5.4.1.7

Where the fuel must be heated, the interlocks and instruments shall reflect the correct values of the variablebeing measured, particularly in dead-end lines, where heavy oil will tend to solidify.

5.4.1.8 Oil Supply.

5.4.1.8.1

The operation of a burner system that has the capability to burn heated and unheated oils shall include aprocedure to ensure that the specified grade of oil, compatible with the selected mode of operation, is beingsupplied to the burner.

5.4.1.8.2

Precautions shall include the intended routing of recirculated oil.

5.4.1.9

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the oil line tothe main burner.

5.4.1.10

Where pressure can develop in excess of the valve or piping rated pressure(s), the piping design shallinclude a means to prevent or relieve excess pressure between the valves.


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5.4.1.11

Oil piping materials and system design shall be in accordance with NFPA 31 (for oil piping inside industrialor institutional buildings), ASME B31.1, Power Piping (for oil piping in power applications), or ASME B31.3,Process Piping (for oil piping in process applications).

5.4.2* Fuel Supply — Gas.

5.4.2.1

The gas supply at the gas service connection shall be controlled at the pressure for which the fuel-burningsystem had been designed.

5.4.2.2

Gas piping shall be sized to maintain the required pressure for maximum burner flow.

5.4.2.3*

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the fuel gasline to the main burner, and an automatic vent valve shall be provided between the two valves.

5.4.2.3.1

When a listed automatic valve-proving system is used with two safety shutoff valves in series, each with aproof of closure switch, the automatic vent valve shall be permitted to be omitted.

5.4.2.3.2*

Where automatic valve-proving systems are installed, valve proving shall be performed either after everyburner shutdown or prior to every burner light-off.

5.4.2.4

Foreign matter such as welding beads, chips, scale, dust, and debris shall be removed from the gas piping.

5.4.2.5

A drip leg shall be provided in the gas piping. (See A.5.4.2.3 and A.5.4.4.1.)

5.4.2.6

Gas piping material and system design shall be in accordance with NFPA 54 (for gas piping inside industrialand institutional buildings), ASME B31.1, Power Piping (for gas piping in power applications), or ASMEB31.3, Process Piping (for gas piping in process applications).

5.4.2.7 Valve Leakage Test.

5.4.2.7.1

Permanent means shall be provided for making manual valve leakage tests of the main burner gas safetyshutoff valves.

5.4.2.7.2

Manual valve leakage tests of the main safety shutoff valves shall be conducted at least annually.

5.4.2.7.3

The use of an automatic valve-proving system shall not eliminate the annual leak test required in 5.4.2.7.2.

5.4.3 Alternate Fuel Firing.

5.4.3.1 Manual Fuel Selection.

Where oil and gas are to be burned alternately, a manual fuel selector switch shall be provided to permitoperation of the necessary interlocks, fuel safety shutoff valves, and controls for the fuel to be fired.

5.4.3.2 Automatic Fuel Selection.

5.4.3.2.1

Where oil and gas are to be burned alternately, an automatic change from one fuel to the other shall beaccomplished only after a shutdown.

5.4.3.2.2

Provisions for manual changeover of the system shall be provided in accordance with 5.4.3.1 andSection 5.8.


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5.4.3.2.3

For simultaneous firing of oil and gas fuels, Section 5.7 shall apply.

5.4.4 Fuel-Burning Equipment.

5.4.4.1* Ignition.

5.4.4.1.1

The main burner shall be equipped with a permanently installed igniter.

5.4.4.1.1.1 Class 1 Igniter.

(A)

Where a Class 1 igniter is used, the main burner flame shall be proven by a flame detector.

(B)

Either the main flame or the igniter flame shall be proven.


(A)

Where a Class 2 igniter is used, it shall not be used to ignite main fuel under uncontrolled or abnormalconditions.

(B)

The burner shall be operated under controlled conditions to limit the potential for abnormal operation aswell as to limit the charge of fuel to the furnace in the event that ignition does not occur during light-off.

(C)

If the Class 2 igniter is not shut down once the main flame sequence is successfully completed, then themain burner flame shall be proven by a flame scanner independently of the igniter.


(A)*

Where a Class 3 igniter is used, the igniter shall be shut down as part of the burner light-off procedurewhen the time trial for ignition of the main burner has expired.

(B)

The use of such igniters to support ignition or to extend the burner control range shall be prohibited.

(C)

The main flame shall be proven by a flame scanner.

5.4.4.1.1.4 Class 3 Special Igniter.

Where a Class 3 special igniter is used, the main burner flame shall be proven by a flame scanner.

5.4.4.1.2

The igniter flame or arc shall impinge on the main burner air-fuel mixture and shall supply ignition energy toprovide immediate ignition of all fuel discharge from the main burner under light-off conditions.

5.4.4.1.3* Igniter Safety Shutoff Valves.

Two safety shutoff valves in series shall be provided in the fuel gas line to the igniter, and an automaticvent valve shall be provided between the two valves.

5.4.4.1.3.1

When a listed automatic valve-proving system is used with two safety shutoff valves in series, the automaticvent valve shall be permitted to be omitted.

5.4.4.1.3.2*

Where an automatic valve-proving system is installed, valve-proving shall be performed either after everyburner shutdown or prior to every burner light-off.


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5.4.4.1.4

The igniter shall be designed for periodic removal, cleaning, and maintenance.

5.4.4.2 Main Burner.

5.4.4.2.1

The main burner shall direct the fuel and air into the furnace so as to provide a stable flame and efficientcombustion over its entire operating range.

5.4.4.2.2

The limits of stable flame for the burner shall be determined by tests.

5.4.4.2.2.1

These tests shall be performed without the igniter in service and shall include the intended range and gradeof fuel(s).

5.4.4.2.2.2*

The tests shall verify that transients that are generated in the fuel and air systems do not adversely affectburner operation.

5.4.4.2.3

Each manual adjustment feature on the burner shall be provided with means for securing it in its intendedposition.

5.4.4.2.4

The atomizing equipment for oil burners shall be designed for periodic removal, cleaning, and maintenance.

5.4.4.2.5

Any procedure for clearing the atomizer and piping into the furnace prior to shutdown shall beaccomplished while the fan is operating and the igniter is re-established or the main flame is provencontinuously during this operation.

5.4.4.2.6

Clearing of the oil passages of the atomizer into the furnace immediately after a shutdown shall beprohibited.

5.4.4.3 Atomizing Medium for Oil Burners.

5.4.4.3.1

Where the fuel is to be atomized with the assistance of another medium, this atomizing medium shall besupplied free of contaminants that could cause an interruption of service.

5.4.4.3.2

The atomizing medium shall be provided at the pressure and temperature specified by the burnermanufacturer.

5.4.4.3.3

Provisions shall be made to ensure that fuel cannot enter the atomizing medium line during or afteroperation.

5.4.4.4 Combustion Air Supply.

5.4.4.4.1

The combustion air supply equipment shall be capable of supplying combustion air for the optimum air-fuelratio over the entire operating range of the burner.

5.4.4.4.2

Provisions shall be made for periodic cleaning of the combustion air supply equipment.

5.4.4.4.3

The requirements for the availability of combustion air shall be determined from NFPA 31 and NFPA 54.


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5.4.4.4.3.1

Louvers and grilles shall be fixed in the open position or interlocked with the equipment so that they areopened automatically or manually during equipment operation. The interlock shall be placed on the drivenmember.

5.4.4.4.3.2

Fans supplying air to the boiler room for combustion shall be interlocked with the burner so that airflow isproven during equipment operation.

5.4.4.5 Furnace.

The furnace shall be designed to promote main burner stability while minimizing zones that cannot bepurged.

5.4.4.6 Combustion Products Removal.

5.4.4.6.1*

The outlet draft equipment shall be capable of removing combustion products without adversely affectingstable flame conditions.

5.4.4.6.2

Where two or more boilers are connected to a common stack, each connection shall be equipped with adamper system.

5.4.4.6.2.1

All boiler outlet dampers shall be equipped with accessible operating and locking devices.

5.4.4.6.2.2

This equipment shall be compatible with the combustion control system of the boiler.

5.4.4.6.2.3

Interlocks shall be provided to prevent firing against a closed damper.

5.4.4.6.2.4

To prevent the interlock from being rendered nonfunctional if the linkage becomes disconnected, one of thefollowing means shall be provided:

(1) Placing the interlock on the driven member

(2) Utilizing a furnace pressure switch

(3) Other approved means

5.4.4.6.2.5

Dampers shall not be required on the outlet of boilers of a type in which maintenance operations areperformed from outside the boiler.

5.4.4.6.3*

Permanently installed flue gas analyzers shall not present an ignition source hazard to the flue gas streambeing sampled.

5.4.5* Combustion Control System.

5.4.5.1

The combustion control system shall be installed in accordance with the requirements of 4.13.1.

5.4.5.2

The combustion control system shall maintain air-fuel mixtures at pre-established ratios throughout theoperating range of the burner and during changes in the firing rate.

5.4.5.3*

The system shall provide limits on fuel and air to prevent furnace input from being reduced below the pointof stable burner operation.


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5.4.5.4

The minimum and maximum points of stable burner operation shall be defined by the burner manufacturerand verified by operational tests.

5.4.6 Interlock System.

5.4.6.1

In addition to the requirements in Section 4.11, the boiler control system for single burner boilers shall bepermitted to be combined with the burner management system under one of the following conditions:

(1)

(2) If the combined boiler control and burner management system is specifically listed or labeled for theapplication; or

(3)

(4)

(5)

5.4.6.2

The system shall be equipped with a method of determining the operating state of each interlock withoutdisassembling any of the interlock devices.

5.4.6.3

Each interlock shall be provided with a method of establishing the set point.

5.4.6.4

Interlock devices shall be designed for anticipated environmental conditions, such as temperature, humidity,vibration, and corrosive agents.

5.4.6.5 Bypass.

5.4.6.5.1

The design shall not require any deliberate defeating of an interlock to start or operate equipment.

5.4.6.5.2

Interlocks shall be permitted to be bypassed as allowed by 5.5.3.2.1(4), and 5.5.3.3.1(4).

5.4.6.5.3

Interlock devices shall be permitted to be temporarily removed from service for maintenance or testing inaccordance with the following:

(1) Removal of the interlock shall be authorized by a competent person and documented in accordancewith operating procedures.

(2) Alternate means shall be substituted to supervise this interlock function in accordance with operatingprocedures.

5.4.6.5.4

The interlocks on the low water cutouts shall be permitted to be bypassed during normal operation forblowdown purposes only.

5.4.6.5.4.1

The bypass of 5.4.6.5.4 shall be of a type that is temporarily held during blowdown.

* If the fuel-air ratio is controlled externally from the boiler control system; or

* A single safety-rated programmable logic system shall be permitted to be used to implement bothburner management system safety and process logic where both of the following conditions are met:

The processor and input/output (I/O) modules are approved or certified by a notified bodyaccording to IEC 61508, Functional Safety of Electrical/Electronic/Programmable ElectronicSafety-Related Systems , to be at least SIL 3 capable; and

The burner management system logic is isolated from other logic and boiler controls, and therelated data of the burner management system program, including I/O data, are protected frombeing unintentionally affected by data of other user programs.


73 of 372 1/9/2017 1:48 PM


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5.4.6.6*

Each safety control ac circuit shall be two wires, one side grounded, and shall be protected with a suitablefuse or circuit breaker in the hot side only.

5.4.6.7 Safety Control dc Circuits.

5.4.6.7.1

Safety control dc circuits shall be arranged as called for in 5.4.6.6 where grounding is possible.

5.4.6.7.2

Where grounding is not possible and the circuit voltage exceeds 50 volts, the circuit shall have switchingcontacts in one side of the line and shall be provided with ground-fault circuit interrupters.

5.4.7 Flame Safety Shutdown System.

5.4.7.1

The response time from flame failure to de-energization of the safety shutoff valves shall not exceed4 seconds.

5.4.7.2

The response time from de-energization of the safety shutoff valves to full closure shall not exceed1 second.

5.4.7.3

Where flame-sensing detectors can fail in the flame-proven mode, self-checking features shall be providedunless the burner is operated for periods less than 24 hours and the burner management system includes asafe-start component checking feature.

5.4.7.4

A safe-start component checking feature shall include a circuit incorporated in the burner managementsystem that prevents light-off if the flame-sensing relay is in the flame-present position due to componentfailure or due to the presence of actual or simulated flame.

5.4.8 Electrical Equipment.

5.4.8.1*

All electrical equipment and wiring shall conform to NFPA 70.

5.4.8.2

Special fuels or applications could require components for hazardous location and shall be reviewed duringthe design of the system.

5.4.9* Gas and Oil Firing: Special Problems.

Systems installed or designed to reduce NOx emissions shall be evaluated to ensure that the performance

of flame safety and combustion control systems are not impaired.

Additional Proposed Changes

File Name Description Approved

85-2015_Chapter_5_Content_to_FUN.docxMaterial in section 5.4 that was included in PI to FUN for inclusion.


The SBB Task Group reviewed the material in section 5.4 and found it to be generic requirements for most fuel systems used within the 85 document. A separate PI was submitted to the FUN Committee to consider including the material into Chapter 4. The SBB Committee will need to take action on this PI based on the results of the work done by FUN on PI No. 172.



74 of 372 1/9/2017 1:48 PM


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Submitter Full Name: John Eibl

Organization: The Chemours Company Inc.

Affilliation: NFPA 85 SBB Task Group

Street Address:

City:

State:

Zip:

Submittal Date: Sat Dec 24 13:25:21 EST 2016


75 of 372 1/9/2017 1:48 PM


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Important Notice: The document has been provided in Microsoft Word format for the purpose of NFPA 85 Task Group work. This document is the copyright property of the National Fire Protection Association (NFPA), Copyright © 2015 NFPA, and may not be used for any other purpose or distributed to any other persons or parties outside of the NFPA Task Group.

Chapter 5 Single Burner Boilers

5.1 Application.

5.1.1

This chapter shall be used in conjunction with Chapters 1 through 4 and requires the coordination of

operation procedures, control systems, interlocks, and structural design.

5.1.2

Where conflicts exist, the requirements of Chapter 5 shall apply.

5.1.3

All safety shutoff valves, safety interlock devices, valve-proving systems, and flame detection

systems shall be listed or approved. A safety shutoff valve proof of closure switch shall be an

original design component of the valve or actuator assembly and shall activate only after the valve is

fully closed.

5.2 Purpose.

The purpose of this chapter shall be to establish minimum requirements for the design, installation,

operation, and maintenance of single burner boilers, their fuel-burning systems, and related systems

to contribute to operation within design limits and, in particular, to the prevention of furnace

explosions.

5.3 Unattended Operation.

The process hazard analysis required by 4.1.4 shall not apply to automatic recycling and automatic

nonrecycling single burner boilers designed for unattended operation unless required by the

authority having jurisdiction.



5.4.1.1

Fuel shall be stored, prepared, and delivered to the oil service connection under anticipated

operating conditions in accordance with the applicable portions of NFPA 31.

5.4.1.2


5.4.1.3

Fuel shall be delivered continuously to the combustion chamber in a finely atomized form that can

be ignited readily and consumed.

5.4.1.4

All equipment that is associated with pumping, heating, and straining the fuel from storage to the

service connection shall be designed, sized, and interconnected so as to provide a fuel supply that

meets the boiler design requirements over a full range of conditions.

Text w/ proposed items moved to FUN

Commented [WG1]: Move to Fundamentals Chapter: 4.E.3 All safety shutoff valves, safety interlock devices, valve-proving systems, and flame detection systems shall be listed or approved. 4.E.3.1 A safety shutoff valve proof of closure switch shall be an original design component of the valve or actuator assembly and shall activate only after the valve is fully closed.

Commented [WG2]: Move to Fundamentals Chapter: 4.A.1* Fuel Supply — Oil.

Commented [WG3]: Move to Fundamentals Chapter: 4.A.1.1 Fuel shall be stored, prepared, and delivered to the oil service connection under anticipated operating conditions in accordance with the applicable portions of NFPA 31.

Commented [WG4]: Move to Fundamentals Chapter: 4.A.1.2 Operation of the burner shall not be attempted until a continuous fuel supply is ensured

Commented [WG5]: Move to Fundamentals Chapter: 4.A.1.3 Fuel shall be delivered continuously to the combustion chamber in a finely atomized form that can be ignited readily and consumed.

Commented [WG6]: Move to Fundamentals Chapter: 4.A.1.4 All equipment that is associated with pumping, heating, and straining the fuel from storage to the service connection shall be designed, sized, and interconnected so as to provide a fuel supply that meets the boiler design requirements over a full range of conditions.

Formatted: Font color: Red


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5.4.1.5


5.4.1.6

Fuel being burned shall be delivered to the burner at the temperature and pressure specified by the

burner manufacturer.

5.4.1.7

Where the fuel must be heated, the interlocks and instruments shall reflect the correct values of the

variable being measured, particularly in dead-end lines, where heavy oil will tend to solidify.

5.4.1.8 Oil Supply.

5.4.1.8.1

The operation of a burner system that has the capability to burn heated and unheated oils shall

include a procedure to ensure that the specified grade of oil, compatible with the selected mode of

operation, is being supplied to the burner.

5.4.1.8.2


5.4.1.9

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the oil

line to the main burner.

5.4.1.10

Where pressure can develop in excess of the valve or piping rated pressure(s), the piping design

shall include a means to prevent or relieve excess pressure between the valves.

5.4.1.11

Oil piping materials and system design shall be in accordance with NFPA 31 (for oil piping inside

industrial or institutional buildings), ASME B31.1, Power Piping (for oil piping in power applications),

or ASME B31.3, Process Piping (for oil piping in process applications).


5.4.2.1

The gas supply at the gas service connection shall be controlled at the pressure for which the fuel-

burning system had been designed.

5.4.2.2


5.4.2.3*

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the fuel

gas line to the main burner, and an automatic vent valve shall be provided between the two valves.

5.4.2.3.1

Commented [WG7]: Move to Fundamentals Chapter: 4.A.1.5 Relief valves shall be installed after the pump to prevent overpressure in the system.

Commented [WG8]: Move to Fundamentals Chapter: 4.A.1.6 Fuel being burned shall be delivered to the burner at the temperature and pressure specified by the burner manufacturer.

Commented [WG9]: Move to Fundamentals Chapter: 4.A.1.7 Where the fuel must be heated, the interlocks and instruments shall reflect the correct values of the variable being measured, particularly in dead-end lines, where heavy oil will tend to solidify.

Commented [WG10]: Move to Fundamentals Chapter: 4.B.1.8 Oil Supply.

Commented [WG11]: Move to Fundamentals Chapter: 4.B.1.8.1 The operation of a burner system that has the capability to burn heated and unheated oils shall include a procedure to ensure that the specified grade of oil, compatible with the selected mode of operation, is being supplied to the burner.

Commented [WG12]: Move to Fundamentals Chapter: 4.B.1.8.2 Precautions shall include the intended routing and flow control of recirculated oil. A.4.B.18.2: Precautions for the oil system may include: oil pressure, temperature, flow control or isolation and monitoring in return line)

Commented [WG13]: Move to Fundamentals Chapter: 4.B.1.9 Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the oil line to the main burner. 4.B.1.9.1 ... [1]

Commented [WG14]: Move to Fundamentals Chapter: 4.B.1.10 ... [2]

Commented [WG15]: Move to Fundamentals Chapter: 4.B.1.11 ... [3]

Commented [WG16]: Move to Fundamentals Chapter: 4.C.2* Fuel Supply — Commercial Grade Fuel Gas. ... [4]

Commented [WG17]: Move to Fundamentals Chapter: 4.C.2.1 ... [5]

Commented [WG18]: Move to Fundamentals Chapter: 4.C.2.2 ... [6]

Commented [WG19]: Move to Fundamentals Chapter: 4.C.2.3* ... [7]

Commented [WG20]: Move to Fundamentals Chapter: 4.C.2.3.1 ... [8]


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When a listed automatic valve-proving system is used with two safety shutoff valves in series, each

with a proof of closure switch, the automatic vent valve shall be permitted to be omitted.

5.4.2.3.2*

Where automatic valve-proving systems are installed, valve proving shall be performed either after

every burner shutdown or prior to every burner light-off.

5.4.2.4

Foreign matter such as welding beads, chips, scale, dust, and debris shall be removed from the gas

piping.

5.4.2.5


5.4.2.6

Gas piping material and system design shall be in accordance with NFPA 54 (for gas piping inside

industrial and institutional buildings), ASME B31.1, Power Piping (for gas piping in power

applications), or ASME B31.3, Process Piping (for gas piping in process applications).


5.4.2.7.1

Permanent means shall be provided for making manual valve leakage tests of the main burner gas

safety shutoff valves.

5.4.2.7.2


5.4.2.7.3

The use of an automatic valve-proving system shall not eliminate the annual leak test required in

5.4.2.7.2.



Where oil and gas are to be burned alternately, a manual fuel selector switch shall be provided to

permit operation of the necessary interlocks, fuel safety shutoff valves, and controls for the fuel to be

fired.


5.4.3.2.1

Where oil and gas are to be burned alternately, an automatic change from one fuel to the other shall

be accomplished only after a shutdown.

5.4.3.2.2

Provisions for manual changeover of the system shall be provided in accordance with 5.4.3.1 and Section

5.8 .

5.4.3.2.3

Commented [WG21]: Move to Fundamentals Chapter: 4.C.2.3.2* Where automatic valve-proving systems are installed, valve proving shall be performed either after every burner shutdown or prior to every burner light-off. A.4.C.2.3.2 It is recommended that valve proving be done at burner shutdown to establish that the gas shutoff valves are tight.

Commented [WG22]: Move to Fundamentals Chapter: 4.C.2.4 Foreign matter such as welding beads, chips, scale, dust, and debris shall be removed from the gas piping.

Commented [WG23]: Move to Fundamentals Chapter: 4.C.2.5 A drip leg shall be provided in the gas piping. (See A.4.C.2.3 and A.4.D.4.1)

Commented [WG24]: Move to Fundamentals Chapter: 4.C.2.6 Gas piping material and system design shall be in accordance with NFPA 54 (for gas piping inside industrial and institutional buildings), ASME B31.1, Power Piping (for gas piping in power applications), or ASME B31.3, Process Piping (for gas piping in process applications).

Commented [WG25]: Move to Fundamentals Chapter: 4.C.2.7 Valve Leakage Test.

Commented [WG26]: Move to Fundamentals Chapter: 4.C.2.7.1 Permanent means shall be provided for making manual valve leakage tests of the main burner gas safety shutoff valves



Commented [WG29]: Move to Fundamentals Chapter: 4.D.3 Alternate Fuel Firing. ... [11]

Commented [WG30]: Move to Fundamentals Chapter: 4.D.3.1 Manual Fuel Selection. ... [12]

Commented [WG31]: Move to Fundamentals Chapter: 4.D.3.2 Automatic Fuel Selection.

Commented [WG32]: Move to Fundamentals Chapter: 4.D.3.2.1 ... [13]


Commented [WG34]: Move to Fundamentals Chapter: 4.D.3.2.3 For simultaneous firing of oil and gas fuels, Section 5.7 shall apply


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5.4.4.1* Ignition.

5.4.4.1.1



(A)


(B)



(A)

Where a Class 2 igniter is used, it shall not be used to ignite main fuel under uncontrolled or abnormal

conditions.

(B)

The burner shall be operated under controlled conditions to limit the potential for abnormal operation as

well as to limit the charge of fuel to the furnace in the event that ignition does not occur during light-off.

(C)

If the Class 2 igniter is not shut down once the main flame sequence is successfully completed, then the

main burner flame shall be proven by a flame scanner independently of the igniter.


(A)*

Where a Class 3 igniter is used, the igniter shall be shut down as part of the burner light-off procedure

when the time trial for ignition of the main burner has expired.

(B)


(C)




5.4.4.1.2

The igniter flame or arc shall impinge on the main burner air-fuel mixture and shall supply ignition energy

to provide immediate ignition of all fuel discharge from the main burner under light-off conditions.


Two safety shutoff valves in series shall be provided in the fuel gas line to the igniter, and an automatic

vent valve shall be provided between the two valves.

5.4.4.1.3.1

When a listed automatic valve-proving system is used with two safety shutoff valves in series, the

automatic vent valve shall be permitted to be omitted.

5.4.4.1.3.2*

Where an automatic valve-proving system is installed, valve-proving shall be performed either after every

burner shutdown or prior to every burner light-off.

5.4.4.1.4


Commented [WG35]: Move to Fundamentals Chapter: 4.D.4 Fuel-Burning Equipment. 4.D.4.1* Ignition. 4.D.1.1 The main burner shall be equipped with a permanently installed igniter. A.4.D.4.1 ... [15]

Commented [WG36]: Move to Fundamentals Chapter: 4.D.4.1.1.1. Class 1 igniter. (A) Where a Class 1 igniter is used, the main burner flame shall be proven by a flame detector. (B) Either the main flame or the igniter flame shall be proven.

Commented [WG37]: Move to Fundamentals Chapter: 4.D.4.1.1.2. Class 2 Igniter (A) Where a Class 2 igniter is used, it shall not be used to ignite main fuel under uncontrolled or abnormal conditions. (B) The burner shall be operated under controlled conditions to limit the potential for abnormal operation as well as to limit the charge of ... [16]

Commented [WG38]: Move to Fundamentals Chapter: 4.D.4.1.1.3 Class 3 Igniter. (A)* Where a Class 3 igniter is used, the igniter shall be shut down as part of the burner light-off procedure when the time trial for ignition of the main burner has expired. ... [17]

Commented [WG39]: Move to Fundamentals Chapter: 4.D.4.1.1.4 Class 3 Special Igniter. Where a Class 3 special igniter is used, the main burner flame shall be proven by a flame scanner.

Commented [WG40]: Move to Fundamentals Chapter: 4.D.4.1.2 The igniter flame or arc shall impinge on the main burner air-fuel mixture and shall supply ignition energy to provide immediate ... [18]

Commented [WG41]: 4.D.4.1.3* Igniter Safety Shutoff Valves. Two safety shutoff valves in series shall be provided in the fuel gas line to the igniter, and an automatic vent valve shall be provided between the two valves. A.4.D.4.1.3 ... [19]

Commented [WG42]: Move to Fundamentals Chapter: 4.D.4.1.3.1 When a listed automatic valve-proving system is used with two safety shutoff valves in series, the automatic vent valve shall be permitted to be omitted.

Commented [WG43]: Move to Fundamentals Chapter: 4.D.4.1.3.2* Where an automatic valve-proving system is installed, valve-proving shall be performed either after every burner shutdown or prior to every burner light-off. ... [20]

Commented [WG44]: Move to Fundamentals Chapter: 4.D.4.1.4 The igniter shall be designed for periodic removal, cleaning, and maintenance.


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5.4.4.2.1

The main burner shall direct the fuel and air into the furnace so as to provide a stable flame and efficient

combustion over its entire operating range.

5.4.4.2.2


5.4.4.2.2.1

These tests shall be performed without the igniter in service and shall include the intended range and

grade of fuel(s).

5.4.4.2.2.2*

The tests shall verify that transients that are generated in the fuel and air systems do not adversely affect

burner operation.

5.4.4.2.3

Each manual adjustment feature on the burner shall be provided with means for securing it in its intended

position.

5.4.4.2.4

The atomizing equipment for oil burners shall be designed for periodic removal, cleaning, and

maintenance.

5.4.4.2.5

Any procedure for clearing the atomizer and piping into the furnace prior to shutdown shall be

accomplished while the fan is operating and the igniter is re-established or the main flame is proven

continuously during this operation.

5.4.4.2.6

Clearing of the oil passages of the atomizer into the furnace immediately after a shutdown shall be

prohibited.


5.4.4.3.1

Where the fuel is to be atomized with the assistance of another medium, this atomizing medium shall be

supplied free of contaminants that could cause an interruption of service.

5.4.4.3.2

The atomizing medium shall be provided at the pressure and temperature specified by the burner

manufacturer.

5.4.4.3.3

Provisions shall be made to ensure that fuel cannot enter the atomizing medium line during or after

operation.


5.4.4.4.1

The combustion air supply equipment shall be capable of supplying combustion air for the optimum air-

fuel ratio over the entire operating range of the burner.

5.4.4.4.2


5.4.4.4.3


5.4.4.4.3.1

Commented [WG45]: Move to Fundamentals Chapter: 4.D.4.2.1 The main burner shall direct the fuel and air into the furnace so as to provide a stable flame and efficient combustion over its entire operating range.

Commented [WG46]: Move to Fundamentals Chapter: 4.D.4.2.2 The limits of stable flame for the burner shall be determined by tests.

Commented [WG47]: Move to Fundamentals Chapter: 4.D.4.2.2.1 These tests shall be performed without the igniter in service and shall include the intended range and grade of fuel(s).

Commented [WG48]: Move to Fundamentals Chapter: 4.D.4.2.2.2* The tests shall verify that transients that are generated in the fuel and air systems do not adversely affect burner operation. A.4.D.4.2.2.2 ... [21]








Commented [WG56]: Move to Fundamentals Chapter: 4.D.4.4 Combustion Air Supply.




Commented [WG60]: Move to Fundamentals Chapter: 4.D.4.4.3.1 ... [32]


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Louvers and grilles shall be fixed in the open position or interlocked with the equipment so that they are

opened automatically or manually during equipment operation. The interlock shall be placed on the driven

member.

5.4.4.4.3.2

Fans supplying air to the boiler room for combustion shall be interlocked with the burner so that airflow is

proven during equipment operation.

5.4.4.5 Furnace.

The furnace shall be designed to promote main burner stability while minimizing zones that cannot

be purged.


5.4.4.6.1*

The outlet draft equipment shall be capable of removing combustion products without adversely

affecting stable flame conditions.

5.4.4.6.2

Where two or more boilers are connected to a common stack, each connection shall be equipped

with a damper system.

5.4.4.6.2.1


5.4.4.6.2.2


5.4.4.6.2.3


5.4.4.6.2.4

To prevent the interlock from being rendered nonfunctional if the linkage becomes disconnected,

one of the following means shall be provided:




5.4.4.6.2.5

Dampers shall not be required on the outlet of boilers of a type in which maintenance operations are

performed from outside the boiler.

5.4.4.6.3*

Permanently installed flue gas analyzers shall not present an ignition source hazard to the flue gas

stream being sampled.


Commented [WG61]: Move to Fundamentals Chapter: 4.D.4.4.3.2 Fans supplying air to the boiler room for combustion shall be interlocked with the burner so that airflow is proven during equipment operation.

Commented [WG62]: Move to Fundamentals Chapter: 4.D.4.6.3* Permanently installed flue gas analyzers shall not present an ignition source hazard to the flue gas stream being sampled. A.4.D.4.6.3 Analyzers could contain heated elements that exceed the autoignition temperature of many fuels. Zirconium oxide analyzers, commonly used for oxygen analysis, contain an element heated to 704°C (1300°F). This high temperature element presents a potential ignition source to unburned fuel that could be present during pre-purge or at startup. Some analyzers are designed to protect the sampled space from the ignition source by providing flashback protection (such as flame arresters in the sample gas path). It should be noted, however, that flame arrestors might only work below a certain temperature which is usually not quantified, might not quench a flame as well once it becomes corroded, and might induce a speed of response delay that could be detrimental to the control or protection strategy. Consideration should be given to powering down analyzers during boiler or fuel trip situations if they can exceed the autoignition temperature of the fuel being fired.


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5.4.5.1


5.4.5.2

The combustion control system shall maintain air-fuel mixtures at pre-established ratios throughout the

operating range of the burner and during changes in the firing rate.

5.4.5.3*

The system shall provide limits on fuel and air to prevent furnace input from being reduced below the

point of stable burner operation.

5.4.5.4

The minimum and maximum points of stable burner operation shall be defined by the burner

manufacturer and verified by operational tests.


5.4.6.1

In addition to the requirements in Section 4.11, the boiler control system for single burner boilers

shall be permitted to be combined with the burner management system under one of the following

conditions:

(1) *If the fuel-air ratio is controlled externally from the boiler control system; or

(2) If the combined boiler control and burner management system is specifically listed or labeled

for the application; or

(3) *A single safety-rated programmable logic system shall be permitted to be used to implement

both burner management system safety and process logic where both of the following conditions

are met:

(a) The processor and input/output (I/O) modules are approved or certified by a notified body

according to IEC 61508, Functional Safety of Electrical/Electronic/Programmable Electronic

Safety-Related Systems, to be at least SIL 3 capable; and

(b) The burner management system logic is isolated from other logic and boiler controls, and

the related data of the burner management system program, including I/O data, are protected

from being unintentionally affected by data of other user programs.

5.4.6.2

The system shall be equipped with a method of determining the operating state of each interlock without

disassembling any of the interlock devices.

5.4.6.3


5.4.6.4

Interlock devices shall be designed for anticipated environmental conditions, such as temperature,

humidity, vibration, and corrosive agents.

5.4.6.5 Bypass.

5.4.6.5.1


Commented [WG63]: Move to Fundamentals Chapter: 4.D.5.2 The combustion control system shall maintain air-fuel mixtures at pre-established ratios throughout the operating range of the burner and during changes in the firing rate.

Commented [WG64]: Move to Fundamentals Chapter: 4.D.5.3* The system shall provide limits on fuel and air to prevent furnace input from being reduced below the point of stable burner operation. A.4.D.5.3 Consideration should be given to the effects of fuel and air pressure and temperature fluctuations as related to the airflow and the performance of the fuel flowmeter in regulating the air-fuel ratio.

Commented [WG65]: Move to Fundamentals Chapter: 4.D.5.4 The minimum and maximum points of stable burner operation shall be defined by the burner manufacturer and verified by operational tests.

Commented [WG66]: Move to Fundamentals Chapter: 4.D.6.2 The system shall be equipped with a method of determining the operating state of each interlock without disassembling any of the interlock devices.

Commented [WG67]: Move to Fundamentals Chapter: 4.D.6.3 Each interlock shall be provided with a method of establishing the set point.

Commented [WG68]: Move to Fundamentals Chapter: 4.D.6.4 Interlock devices shall be designed for anticipated environmental conditions, such as temperature, humidity, vibration, and corrosive agents.

Commented [WG69]: Move to Fundamentals Chapter: 4.D.6.5 Bypass.

Commented [WG70]: Move to Fundamentals Chapter: 4.D.6.5.1 The design shall not require any deliberate defeating of an interlock to start or operate equipment.


of 249


5.4.6.5.2


5.4.6.5.3

Interlock devices shall be permitted to be temporarily removed from service for maintenance or testing in

accordance with the following:

(1) Removal of the interlock shall be authorized by a competent person and documented in accordance

with operating procedures.

(2) Alternate means shall be substituted to supervise this interlock function in accordance with operating

procedures.

5.4.6.5.4

The interlocks on the low water cutouts shall be permitted to be bypassed during normal operation for

blowdown purposes only.

5.4.6.5.4.1


5.4.6.6*

Each safety control ac circuit shall be two wires, one side grounded, and shall be protected with a suitable

fuse or circuit breaker in the hot side only.


5.4.6.7.1


5.4.6.7.2

Where grounding is not possible and the circuit voltage exceeds 50 volts, the circuit shall have switching

contacts in one side of the line and shall be provided with ground-fault circuit interrupters.


5.4.7.1

The response time from flame failure to de-energization of the safety shutoff valves shall not exceed 4

seconds.

5.4.7.2

The response time from de-energization of the safety shutoff valves to full closure shall not exceed 1

second.

5.4.7.3

Where flame-sensing detectors can fail in the flame-proven mode, self-checking features shall be

provided unless the burner is operated for periods less than 24 hours and the burner management

system includes a safe-start component checking feature.

5.4.7.4

A safe-start component checking feature shall include a circuit incorporated in the burner management

system that prevents light-off if the flame-sensing relay is in the flame-present position due to component

failure or due to the presence of actual or simulated flame.


5.4.8.1*


5.4.8.2

Special fuels or applications could require components for hazardous location and shall be reviewed

during the design of the system.

Commented [WG71]: Move to Fundamentals Chapter: 4.D.6.5.2 Interlocks shall be permitted to be bypassed as allowed by 5.5.3.2.1(4) and 5.5.3.3.1(4).

Commented [WG72]: Move to Fundamentals Chapter: 4.D.6.5.3 Interlock devices shall be permitted to be temporarily removed from service for maintenance or testing in accordance with the following: (1) Removal of the interlock shall be authorized by a competent person and documented in accordance with operating procedures. (2) Alternate means shall be substituted to supervise this interlock function in accordance with operating procedures.

Commented [WG73]: Move to Fundamentals Chapter: 4.D.6.5.4 The interlocks on the low water cutouts shall be permitted to be bypassed during normal operation for blowdown purposes only.

Commented [WG74]: Move to Fundamentals Chapter: 4.D.6.5.4.1 The bypass of 4.D.6.5.4 shall be of a type that is temporarily held during blowdown.

Commented [WG75]: Move to Fundamentals Chapter: 4.D.6.6* ... [33]

Commented [WG76]: Move to Fundamentals Chapter: 4.D.6.7 Safety Control dc Circuits.



Commented [WG79]: Move to Fundamentals Chapter: 4.D.7 Flame Safety Shutdown System. ... [36]

Commented [WG80]: Move to Fundamentals Chapter: 4.D.7.3 ... [37]


Commented [WG82]: Move to Fundamentals Chapter: 4.D.8 Electrical Equipment.

Commented [WG83]: Move to Fundamentals Chapter: 4.D.8.1* All electrical equipment and wiring shall conform to NFPA 70. ... [39]



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Systems installed or designed to reduce NOx emissions shall be evaluated to ensure that the

performance of flame safety and combustion control systems are not impaired.

5.5 Starting of a Cold Boiler.

5.5.1 General.

5.5.1.1

Starting of a cold boiler shall be accomplished in conformance with the manufacturer's

recommendations.

5.5.1.2

In no case shall a boiler that has been taken out of service for maintenance, repair, or extended

shutdown be started from a cold condition without a trained operator present.

5.5.1.3 Start-Up Procedures.

5.5.1.3.1

Applicable start-up procedures for the provided boiler shall be followed.

5.5.1.3.2

The firing rate shall be limited in accordance with the boiler manufacturer's instructions.

5.5.2 Gas-Fired Boilers.

The procedures of Section 5.6 shall be followed for starting a cold gas-fired boiler.

5.5.3 Oil-Fired Burners.

When steam is not available for heating oil, as an atomizing medium, or for driving auxiliary

equipment, one of the starting methods described in 5.5.3.1 , 5.5.3.2 , or 5.5.3.3 shall be used.

5.5.3.1 Auxiliary Air Atomizing of Oil.

When auxiliary air atomizing of oil is used for a cold start-up, all the equipment, facilities, and

procedures listed in 5.5.3.1.1 , 5.5.3.1.2 , and 5.5.3.1.3 shall be required.

5.5.3.1.1 Required Equipment.

The following equipment shall be required:

(1) Forced draft (FD) fan

(2) Approved auxiliary oil heater for start-up fuel flow with a capacity not less than that required for

minimum fire with stable flame (only for fuel oils that require heating)

(3) Check valves in steam and air lines to the atomizer

5.5.3.1.2* Required Facility.

An alternate atomizing air supply shall be required.

5.5.3.1.3 Starting Procedure.

Commented [WG85]: Move to Fundamentals Chapter: 4.D.9* Gas and Oil Firing: Special Problems. Systems installed or designed to reduce NOx emissions shall be evaluated to ensure that the performance of flame safety and combustion control systems are not impaired. A.4.D.9 The special problems of low NOx operation include the following: (1)Air pollution control regulations require that new installations meet NOx emission limits that are lower than emissions now obtained from many of the currently installed firing systems and furnace designs that are using past operating procedures. In addition, air quality regulations in some local areas require a reduction of NOx emissions from existing boilers. (2)To achieve those reductions, one or more of the following methods should be used: (a)Low excess air firing (i.e., less than the “normal” 10 percent to 25 percent excess air) (b)Multistage air admission, involving the introduction of combustion air in two or more stages partly at the fuel nozzle, which could be less than stoichiometric air, and partly by independent admission through special furnace ports; and a second stage of air admission within the same burner housing (c)Flue gas recirculation into all or a portion of the secondary air (d)Reduced secondary air temperature (e)Fuel staging (f)On new units, introduction of new burner and furnace designs by equipment manufacturers (3)Generally, the effect of all these methods is to produce lower flame temperatures and longer, less turbulent flames, which result in lower NOx. The hazards of low NOx firing methods include the following: (1)The following methods have important implications with regard to furnace safety, particularly for existing units, and could introduce unacceptable risks if proper precautions are not taken: (a)Fuel-firing systems that are designed to reduce NOx emissions tend to reduce the margins formerly available to prevent or minimize accumulations of unburned fuel in the furnace during combustion upsets or flameouts. Thus, it is important to trip fuel on loss of flame. (b)These methods can narrow the limits of stable flames that are produced by the burner system. The tests, which are specified in 4.D.4.2.2 5.4.4.2.25.4.4.2.25.4.4.2.25.4.4.2.25.3.4.2.2, should be repeated on existing units when any of these methods is employed. (c)When flue gas recirculation is used, equipment should be provided to ensure proper mixing and uniform distribution of recirculated gas and the combustion air. When flue gas recirculation is introduced into the total combustion air stream, equipment should be provided to monitor either the ratio of flue gas to air or the oxygen content of the mixture. When flue gas recirculation is introduced so that only air and not the mixture is introduced at the burner, proper provisions should be made to ensure the prescribed distribution of air and the recirculating flue gas–air mixture. (d)All the methods tend to increase the possibility of an unstable flame and unburned combustibles throughout the unit and ducts. Therefore, recommendations of the boiler, burner, and instrument manufacturers should be followed, or tests should be conducted to verify operating margins. (2)Any change in flame characteristics to reduce NOx emissions can require changing either or both the type and the location of flame detectors on existing units.


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The following procedural steps shall be followed:

(1) Circulate and heat oil, using auxiliary heater and recirculating system, to satisfy all interlocks,

where included.

(2) Follow the prefiring and light-off cycles as described in Section 5.6 , using air as the atomizing

medium.

(3) Set combustion control at the light-off firing rate.

(4) When steam pressure has reached the point required for heating and atomizing the oil, shut

down in accordance with the normal shutdown procedure described in Section 5.6 .

(5) Close the atomizing air supply and open the atomizing steam supply, making certain that dry

steam is available.

(6) Change over from auxiliary oil heater to steam oil heater.

(7) Continue the boiler start-up sequence.

5.5.3.2 Auxiliary Mechanical Atomizing of Heavy Oil.

When auxiliary mechanical atomizing of heavy oil is used for a cold start-up, all the equipment,

facilities, and procedures in 5.5.3.2.1 and 5.5.3.2.2 shall be required.


The following equipment and facilities shall be required:

(1) FD fan.


minimum fire with stable flame.

(3) Mechanical atomizer.

(4) Means to bypass atomizing medium interlocks. The bypassed interlocks shall be made evident

to the operator by means of warning devices.



(1) Circulate and heat oil using auxiliary heater and recirculating systems to satisfy oil interlocks,

where included.

(2) Bypass atomizing medium interlocks. [See 5.5.3.2.1(4) .]

(3) Insert mechanical atomizer.

(4) Follow the prefiring and light-off cycles as described in Section 5.6 .



down in accordance with the normal shutdown procedure as described in Section 5.6 .

(7) Remove the mechanical atomizer.


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(8) Insert the steam atomizer.

(9) Make the atomizing medium interlocks operable and place into service.



5.5.3.3 Auxiliary Mechanical Atomizing of Light (Unheated) Oil.

When auxiliary mechanical atomizing of light (unheated) oil is used for a cold start-up, all the

equipment, facilities, and procedures in 5.5.3.3.1 through 5.5.3.3.3 shall be required.



(1) FD fan.


(3) Check valves in the heavy and light oil lines.



5.5.3.3.2 Required Facility.

A light oil supply shall be required.



(1) Shut off heavy oil to the system.

(2) Insert the mechanical atomizer.

(3) Bypass heavy oil and atomizing medium interlocks. [See 5.5.3.3.1(4) .]

(4) Open the light oil supply into the system.

(5) Follow prefiring and light-off cycles described in Section 5.6 .

(6) Set combustion control at the light-off rate.

(7) When steam pressure has reached the point required for heating and atomizing the heavy oil,

shut down in accordance with the normal shutdown procedure as described in Section 5.6 .

(8) Shut off the light oil supply to the system.



(11) Make the heavy oil and atomizing medium interlocks operable by removing bypasses.

(12) Open the heavy oil supply to the system.



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5.6 Operating Systems.

5.6.1* General.

This section shall be used to define requirements for automatic recycling and automatic

nonrecycling operating systems.

5.6.1.1

Manual systems shall not be installed for new installations or major alterations.

5.6.1.2

Different arrangements shall be permitted if they provide protection and meet the intent of this code.

(See Figure A.5.4.1, Figure A.5.4.2.3, and Figure A.5.4.4.1 for typical arrangements.)

5.6.2 Automatic (Recycling) Systems for Watertube Boilers.

5.6.2.1

An automatic (i.e., recycling) unit shall not be started from a cold condition unless a trained operator

is present.

5.6.2.2

Underlying all the requirements of 5.6.2 shall be the premise that the unit is hot and that steam

pressure and operating water level shall have been established.

5.6.2.3

The fuel to be fired shall have been manually selected.

5.6.2.4

The alternate fuel system shall be placed in a nonfiring condition, and the manual burner valve(s)

shall be closed.

5.6.2.5

An igniter as specified in 5.4.4.1.1 shall be provided.

5.6.2.6

An automatic (i.e., recycling) unit shall recycle on high steam pressure, high water temperature, or

low water level (not determined by the auxiliary low water cutout) and perform four major functions

as given in 5.6.2.6.1 through 5.6.2.6.4.4 .

5.6.2.6.1 Prefiring Cycle.

The prefiring cycle shall accomplish the following steps in the listed order, except that the order of

steps (5), (6), and (7) in the sequence shall be permitted to vary:

(1) Prove the main fuel safety shutoff valves are closed.

(2) Prove no flame is present at the burner.

(3) Start the fan.

(4) Satisfy the fan interlock.


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(5) Where an atomizing medium is used and if not already on, admit medium to main burner.

(6) Where an atomizing medium is used, satisfy the atomizing medium interlocks.

(7) Satisfy fuel interlocks.

(8) Prove the purge airflow by satisfying one of the following items:

(a) Air pressure and “open damper” interlocks for all dampers in the flow path

(b) Airflow interlock

(9) Purge airflow must reach no less than 70 percent of the airflow required at maximum

continuous capacity of the unit.

(10) The purge must be for at least eight air changes. Airflow during the period of opening the

damper and returning it to light-off position is permitted to be included in computing the time for

eight air changes.

(11) Set controls to light-off position.

(12) Prove the dampers and fuel control valve are in light-off position.

(13) If a flue gas recirculation system is supplied, then it shall be purged per the manufacturer's

instructions.

5.6.2.6.2 Light-Off Cycle.


The light-off cycle for a burner with a Class 3 igniter shall accomplish the following in the listed

order:

(1) *Energize the ignition transformer and igniter fuel valves.

(2) Prove igniter flame within 10 seconds of the energization of the igniter fuel valves; for a Class

3 special igniter, proof of igniter operation is not required.

(a) If proven, admit fuel to main burner. For an oil burner other than a return flow type,

simultaneously shut off oil-recirculating flow.

(b) If not proven, establish safety shutdown.

(3) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6

oils, shut off igniter.

(4) Prove main flame (see 5.4.4.1.1.3 and 5.4.4.1.1.4 ) and proceed as follows:

(a) If proven, release to modulating control where provided.




order:



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(2) Prove igniter flame within 10 seconds of the energization of the igniter fuel valves and proceed

as follows:

(a) If proven, admit fuel to the main burner. For an oil burner other than a return flow type,

simultaneously shut off the recirculating flow.



oils, prove the main flame (see 5.4.4.1.1.2 ) and proceed as follows:

(a) If proven, release to combustion control for modulation, where provided.




order:



as follows:


simultaneously shut off recirculating flow.






5.6.2.6.3 Modulation.

Modulation, where provided, shall be accomplished by a combustion control system.

5.6.2.6.4 Shutdown.

5.6.2.6.4.1 Normal Shutdown.

For automatic (i.e., recycling) boilers, high steam pressure, high water temperature, or low water

level (not determined by the auxiliary low water cutout) shall accomplish a normal shutdown, and the

burner shall be allowed to recycle when steam pressure, water temperature, or water level has

returned to within the preset operating range.

5.6.2.6.4.2 Normal Shutdown Cycle.

The normal shutdown cycle shall accomplish the following in the listed order:

(1) Shut off the fuel supply to the main burner.

(2) For oil, proceed as follows:


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(a) If a Class 1 igniter is used, use the manufacturer's instructions to purge the main burner

oil gun prior to continuing the normal shutdown.

(b) Where used, open the recirculating valve.

(c) Shut off atomizing medium, if required by operating procedures.

(3) Shut off the fuel supply to the igniter if in operation.

(4) Perform a postpurge of the furnace and boiler gas passes; the duration of the postpurge must

be no less than 15 seconds at an airflow rate not exceeding that at which the unit was shut down.

(5) Shut down the fan, if required by operating procedures.

5.6.2.6.4.3* Safety Shutdown.

Any of the conditions in 5.6.2.6.4.3(A) or 5.6.2.6.4.3(B) shall accomplish a safety shutdown, and the

burner shall not be allowed to recycle until a trained operator determines the cause of the shutdown

and takes the necessary corrective action to ensure that conditions are within specified operating

limits prior to restarting.

(A)

Oil conditions shall include the following:

(1) Low fuel pressure

(2) Low temperature of heated oils

(3) Loss of combustion air supply

(4) Loss of or failure to establish flame

(5) Loss of control system actuating energy

(6) Power failure

(7) Low water level as determined by the auxiliary low water cutout

(8) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches (one

located at the service connection and the other at the burner, either one of which shall initiate a

safety shutdown on low pressure)

(9) Excessive steam pressure or water temperature

(10) High temperature of heated oil

(B)

Gas conditions shall include the following:

(1) High gas pressure

(2) Low gas pressure




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(6) Power failure



5.6.2.6.4.4 Safety Shutdown Cycle.

The safety shutdown cycle shall accomplish the following in the listed order and shall activate an

alarm:


(2) Shut off the fuel supply and interrupt spark to the igniter if in operation.


(a) Where used, open the recirculating valve.

(b) Where used, shut off the atomizing medium, if required by operating procedures.

(4) Where the inerting system is used, energize it simultaneously with 5.6.2.6.4.4(1) .

(5) Perform a postpurge of the furnace and boiler gas passes. The duration of the postpurge must


(6) After postpurge, shut down the fan, if desired.

(7) Require manual reset.

5.6.3 Automatic (Nonrecycling) Systems for Watertube Boilers.

5.6.3.1

The provisions of 5.6.2.1 , 5.6.2.3 , 5.6.2.5 , and 5.6.2.6 shall apply.

5.6.3.2

The provisions of 5.6.2.6.4.1 shall not apply.

5.6.3.3

When high steam pressure, high water temperature, or low water level establishes a normal

shutdown, the burner shall not be allowed to recycle.

5.6.3.4

A trained operator shall initiate the restart.

5.6.4 Automatic (Recycling) Systems for Firetube Boilers.

5.6.4.1

Underlying all the requirements of 5.6.4 shall be the premise that the equipment is in accordance

with Section 5.4 , that the boiler has been placed in service in accordance with Section 5.6 , and that

the operating water level has been established.

5.6.4.2


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as given in 5.6.4.2.1 through 5.6.4.2.4.4(B) .



steps 5.6.4.2.1(5), 5.6.4.2.1(6), and 5.6.4.2.1(7) in the sequence shall be permitted to vary:

(1) Prove the fuel safety shutoff valves are closed.

(2) Prove no flame is present at burner.

(3) Start the fan.


(5) Where an atomizing medium is used and if not already on, admit the medium to the main

burner.


(7) Satisfy the fuel interlocks.

(8) Prove purge airflow by satisfying one of the following two items:





(10) The purge of the furnace and boiler gas passes must be for at least four air changes and

under the following conditions:

(a) During the purge, the air damper must be driven to the full open position.

(b) Airflow during the time to open the damper and return it to light-off position is permitted to

be included in computing the time for four air changes.

(11) Prove the control system is in light-off position.


instructions.


The light-off cycle shall accomplish the following in the listed order:


(2) Prove the igniter flame within 10 seconds of the energization of the igniter fuel valves and

proceed as follows (for a Class 3 special igniter, proof of igniter operation is not required):

(a) If proven, admit fuel to main burner.



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oils, shut off the igniter.

(4) Prove the main flame and proceed as follows:





5.6.4.2.4 Shutdown.






(b) Where the manufacturer's instructions permit, purging the main burner oil gun in

conjunction with the operation of its igniter is permitted.

(c) Where used, shut off the atomizing medium, if required by operating procedures.



(4) After postpurge, shut down the fan, if required by operating procedures.


High steam pressure, high water temperature, or low water (not determined by the auxiliary low

water cutoff) shall accomplish a normal shutdown, and the burner shall be allowed to recycle when

steam pressure, water temperature, or water level has returned to within the preset operating range.


The safety shutdown cycle shall accomplish the following in the listed order:


(2) Shut off the fuel supply and interrupt the spark to the igniter, if in operation.








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(A)


(1) Low oil pressure






(7) Loss of atomizing medium where used


(9) Power failure


(B)









(8) Power failure

5.6.5 Automatic (Nonrecycling) Systems for Firetube Boilers.

5.6.5.1

The provisions of 5.6.4.1 and 5.6.4.2 shall apply, except that 5.6.4.2.4.2 shall not apply.


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5.6.5.2



5.6.5.3


5.6.6 Manual Supervised Burner Management Systems for Oil-Fired Watertube Boilers.

5.6.6.1

For oil-fired watertube boilers, the steps listed in Table 5.6.6.1(a) through Table 5.6.6.1(d) shall be

taken by a trained operator when starting a manual supervised unit, and the indicated interlocks

shall be satisfied at each step.

Table 5.6.6.1(a) Oil-Fired Watertube Boilers: Prefiring Cycle

Operator Actions* Interlock Functions

(1) Check that fuel safety or

supervisory shutoff valve is closed. (1) Fuel safety or supervisory shutoff valve is closed.

(2) Start fan. (2) Fan is on.

(3) Where used, open atomizing

medium valve. (3) Atomizing medium supply is available.

(4) Open damper(s) to purge

position.

(4) (a) Air pressure and open damper(s) or (b) airflow. [See

5.6.2.6.1(9) and 5.6.2.6.1(10).]

(5) Start purge timer. (5) Purge is complete.

(6) Place damper and fuel control

valve in light-off position.

(6) Damper and fuel control valve are in light-off position. If light-off

airflow is less than purge airflow rate, start light-off time limit timer.

(7) None. (7) Spark, igniter, and main safety shutoff valves are ready for

operation.

*In listed order.

Table 5.6.6.1(b) Oil-Fired Watertube Boilers: Light-Off Cycle


(1) Energize ignition transformer and igniter


(1) Prove igniter flame within 10 seconds of

energization of igniter fuel valves. (For Class 3 special

igniter, proof of igniter operation is not required.)

(2) Open fuel safety shutoff valve to main burner. (2) None.

(3) Close recirculating valve, where used. (3) None.

(4) Open manual fuel shutoff valve. (4) Prove main flame within 10 seconds for Nos. 2

and 4 oils or 15 seconds for Nos. 5 and 6 oils. Close


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igniter safety shutoff valve(s).

(5) Bring unit to present operating pressure at

rate specified by manufacturer, maintaining air-

fuel ratios as established by tests.

(5) None.

(6) On reaching preset pressure range, change

to automatic combustion control. (6) None.

*In listed order.

Table 5.6.6.1(c) Oil-Fired Watertube Boilers: Normal Shutdown Cycle


(1) Shut off fuel supply to main burner.

(1) Fuel safety shutoff

valve(s) to main burner is

closed.

(2) Open fuel recirculating valve, where used. (2) None.

(3) Shut off atomizing medium, where used. (3) None.

(4) Remove fuel atomizer. (4) None.

(5) Perform postpurge of furnace and boiler gas passes. Duration of

postpurge must be no less than 15 seconds at airflow rate not exceeding

that at which unit was shut down.

(5) None.

(6) After postpurge, fan can be permitted to be shut down. (6) None.

*In listed order.

Table 5.6.6.1(d) Oil-Fired Watertube Boilers: Safety Shutdown Cycle


(1) None.

(1) Shut off fuel supply to main burner;

shut off fuel supply and interrupt spark

to igniter, if in operation.

(2) Perform postpurge of furnace and boiler gas passes.

Duration of postpurge must be no less than 15 seconds at

airflow rate not exceeding that at which unit was shut down.

(2) None.


*In listed order.

5.6.6.1.1

Fuel pressure and temperature, atomizing medium, control system energy, power, and water level

shall have been established.


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5.6.6.1.2

When interlocks have been satisfied, this fact shall be indicated to the operator.

5.6.6.2

The fuel to be fired shall be selected.

5.6.6.2.1

The alternate fuel system shall be placed in a nonfiring condition.

5.6.6.2.2

The supervisory or safety shutoff valve(s) shall be closed.

5.6.6.3


5.6.6.4*

Any of the following conditions shall accomplish a safety shutdown, and the burner shall not be

restarted until a trained operator goes out to the boiler, determines the cause of the shutdown, and

takes the necessary corrective action to ensure that conditions are within specified operating limits

prior to restarting:

(1) Low pressure in the fuel supply


(3) Loss or failure to establish flame


(5) Power failure


(7) Loss of atomizing medium


5.6.6.5

Where oil heating is provided, either of the following conditions shall cause alarms to sound:

(1) Low oil temperature

(2) High oil temperature

5.6.7 Manual Supervised Burner Management Systems for Gas-Fired Watertube Boilers.

5.6.7.1

For gas-fired watertube boilers, the steps listed in Table 5.6.7.1(a) through Table 5.6.7.1(d) shall be



Table 5.6.7.1(a) Gas-Fired Watertube Boilers: Prefiring Cycle


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(1) Check that gas safety shutoff

valves are closed. (1) Gas safety shutoff valves are closed.

(2) Start fan. (2) Fan motor is on.


position.


5.6.2.6.1(9) and 5.6.2.6.1(10).]


(5) Place damper and gas

control valve in light-off position.



(6) None. (6) Spark and igniter and main safety shutoff valves are ready for

operation.

*In listed order.

Table 5.6.7.1(b) Gas-Fired Watertube Boilers: Light-Off Cycle



safety shutoff valve(s).

(1) Prove igniter flame within 10 seconds of the



(2) Open gas safety shutoff valves to main

burner.

(2) Prove main flame is within 10 seconds. Close


(3) Bring unit to preset operating pressure at



(3) None.

(4) On reaching preset range, change to

automatic combustion control. (4) None.

*In listed order.

Table 5.6.7.1(c) Gas-Fired Watertube Boilers: Normal Shutdown Cycle

Operator Actions* Interlock

Functions

(1) Shut off gas supply to main burner and to igniter, if in operation, and interrupt spark. (1) None.

(2) Perform postpurge of furnace and boiler gas passes. Duration of postpurge must be

no less than 15 seconds at airflow rate not exceeding that at which unit was shut down. (2) None.


*In listed order.

Table 5.6.7.1(d) Gas-Fired Watertube Boilers: Safety Shutdown Cycle


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(1) None.

(1) Shut off gas supply to main burner, shut off

fuel supply, and interrupt spark to igniter, if in

operation. Where used, simultaneously energize

inerting system.

(2) Perform postpurge of furnace and boiler gas

passes. Duration of postpurge must be no less than

15 seconds at an airflow rate not exceeding that at

which unit was shut down.

(2) None.

(3) After postpurge, fan can be permitted to be shut

down. (3) None.

*In listed order.

5.6.7.1.1

Control system energy, power, and water level shall have been established.

5.6.7.1.2


5.6.7.2


5.6.7.2.1


5.6.7.2.2


5.6.7.3


5.6.7.4









(5) Loss of control systems actuating energy


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(6) Power failure



5.6.8 Soot Blowing.

Where soot blowers are used, the following shall apply:

(1) Soot blowing at nonoptimum air-fuel ratios has been known to lead to explosive formations of

air-soot clouds within the boiler and shall be avoided.

(2) Soot blowers shall be operated only while burners are firing at rates such that the burner flame

cannot be extinguished.

(3) Boilers that are equipped with automatic soot-blowing equipment shall have their controls

interlocked to prevent operation when the burner is shut down or in the prefiring or light-off cycles.

5.7 Simultaneous Firing of Oil and Gas Fuels.

5.7.1* General.

The equipment and procedures required in 5.7.1.1 through 5.7.1.3 shall be used to avoid a

hazardous furnace condition when firing oil and gas simultaneously in a single burner boiler on a

continuous basis.

5.7.1.1

Class 1 or Class 2 igniters shall be used during the light-off of the second fuel as required by the

manufacturer or as established by test.

5.7.1.2

Each boiler shall be tested during initial start-up to determine whether any modifications to the

procedures specified in Section 5.6 are required to establish ignition or to satisfy other design

limitations during light-off, warm-up, or normal operation.

5.7.1.3

The initial prefiring cycle, light-off cycle, and normal shutdown cycles for the initial fuel to be fired

and for single fuel operation shall be completed in accordance with Section 5.6 .

5.7.2 Equipment Requirements.

The following equipment shall be provided for continuous firing of both oil and gas:

(1) A burner that is capable of burning either oil or gas fuel individually or both fuels

simultaneously

(2) A combustion control system that is capable of performing the following functions:

(a) Metering and totaling the inputs from both gas and oil fuels alone or in any combination

(b) Proportioning the total fuel input of each fuel individually or in any combination to total

airflow in order to maintain the air-fuel ratio within design limits


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(c) Limiting fuel demand to be less than measured airflow and limiting air demand to be

greater than measured fuel flow

(d) For items 5.7.2(2) (a) through 5.7.2(2) (c), a control system that is designed to

accommodate a fixed amount of secondary fuel without metering and totaling all fuels shall be

permitted, provided the system maintains air-fuel ratios within design limits throughout the

entire operating range of the burner

(e) Limiting total fuel input to the maximum capacity of the boiler

(f) Controlling and maintaining a minimum airflow rate that takes into account simultaneous

fuel inputs

(g) Controlling and maintaining minimum input rates of each fuel

(h) Requiring a stable return to design air-fuel ratio after the trip or shutdown of either fuel

(3) A safety interlock system with the following capabilities:

(a) Meets the requirements of 5.4.6 for each fuel being fired

(b) Requires, on an interlock action specific to only one of the fuels being fired, that this

particular fuel automatically shut down with operation continuing on the unaffected fuel in a

stable manner; shutdown of both fuels permitted

(c) Requires that both the first and second fuels be introduced with their flow control valves in

light-off positions

(d) Provides for the introduction of the second fuel without requiring a boiler purge

(e) Requires a manual reset following any interlock shutdown

(f) Prohibits the simultaneous light-off of both fuels

(g) Requires flame detector(s) in accordance with 5.4.4 to supervise any of the following

conditions:

(5.7.2(3)(g)1.) Igniter flame as permitted by igniter class

(5.7.2(3)(g)2.) Gas firing

(5.7.2(3)(g)3.) Oil firing

(5.7.2(3)(g)4.) Combined gas and oil firing

(h) Burner flame detectors permitted to supervise multiple fuels

5.7.3 Simultaneous Firing of Oil and Gas Fuels (Automated Second Fuel Start).

This subsection shall define the requirements and procedures for an automated light-off and

subsequent operation on a continuous basis of a second fuel.

5.7.3.1 Equipment Requirements.

Equipment requirements shall be in accordance with 5.7.2 and 5.7.3.2 .

5.7.3.2


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A fuel transfer mode with the following functions shall be provided:

(1) A gas-firing mode in which oil cannot be fired

(2) An oil-firing mode in which gas cannot be fired

(3) A gas-oil-firing mode that permits simultaneous firing of both fuels

(4) The capability to signal the combustion control system to bias up the airflow, to position the

control valve for the second fuel to light-off, and to open the safety shutoff valve(s) of the fuel being

introduced

(5) The capability to bias up the airflow by a preset value in response to a fuel transfer signal while

the airflow remains in automatic mode

5.7.3.3 Subsequent Fuel Light-Off — Oil.

When oil is introduced as the second fuel, the light-off cycle for the oil shall accomplish the following

in the listed order:

(1) Place fuel gas flow and airflow control loops in automatic mode.

(2) Satisfy oil fuel system interlocks.

(3) Install oil atomizer.

(4) Open atomizing medium shutoff valve.

(5) Select dual fuel firing.

(6) Set oil control valve in light-off position.

(7) Prove fuel oil control valve in light-off position.

(8) With airflow in automatic mode, gradually bias up airflow by a preset amount corresponding to

fuel input of fuel oil in light-off.

(9) Establish ignition energy in accordance with manufacturer's instructions. Where an igniter is

required, see 5.6.2.6.2 , 5.6.2.6.2.2 , or 5.6.2.6.2.3 for operating requirements.

(10) Open oil safety shutoff valves and establish oil flow through the burner.

(11) Gradually remove airflow bias.

(12) Verify stable flame and that the air-fuel ratio is within design limits.

(13) Place the combustion control system into the required mode for controlling input rate of each

fuel.

(14) Shut down igniter as required.

5.7.3.4 Subsequent Fuel Light-Off — Gas.

When gas is introduced as the second fuel, the light-off cycle for the gas shall accomplish the

following in the listed order:

(1) Place fuel oil flow and airflow control loops in automatic mode.

(2) Satisfy gas fuel system interlocks.


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(4) Set gas control valve in light-off position.

(5) Prove fuel gas control valve in light-off position.


fuel input of fuel gas in light-off.



(8) Close the vent valve (where used), open the gas safety shutoff valves, and establish gas flow

to the burner.




fuel.


5.7.4 Simultaneous Firing of Oil and Gas Fuels (Manual Second-Fuel Start).

This subsection shall define the requirements and procedures required for the manual light-off and




5.7.4.2

The combustion control system shall have the capability to manually bias up the airflow while the

airflow remains in automatic mode.

5.7.4.2.1

Either the oxygen trim or airflow control station shall be permitted to be used.



in the order listed:

(1) Verify that fuel gas flow and airflow control loops are in automatic mode.




(5) Place oil control valve in light-off position.




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(11) Place the combustion control system into the required mode for controlling the input rate of

each fuel.



When gas is introduced as the second fuel, the procedure shall be in the following order:

(1) Verify that fuel oil flow and airflow control are in the automatic mode.


(3) Place the gas control valve in light-off position.



(5) Establish ignition energy in accordance with manufacturer’s instructions. Where an igniter is



to the burner.




fuel.


5.7.5 Shutdown Cycle.

5.7.5.1 Normal Oil Shutdown Cycle.

The normal shutdown procedure for oil while continuing to fire gas shall be in the following order:

(1) Reduce the oil flow to the light-off rate.

(2) Shut off the oil supply to the burner and open the oil recirculating valve, where used.

(3) Verify stable flame and adjust air-fuel ratio in preparation for purging the oil atomizer.

(4) Purge oil passages of the oil atomizer.

(5) Shut off the atomizing medium, if required.

(6) Remove the oil atomizer from the burner, if required.


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(7) Verify stable flame and that the air-fuel ratio of the gas fire is within design limits.

5.7.5.2 Normal Gas Shutdown Cycle.

The normal shutdown procedure for gas while continuing to fire oil shall be in the following order:

(1) Reduce the gas flow to the light-off rate.

(2) Shut off the gas supply to the burner.

(3) Verify stable flame and that the air-fuel ratio of the oil fire is within design limits.

5.7.5.3* Oil Safety Shutdowns.

5.7.5.3.1

Any of the following operating conditions shall accomplish a safety shutdown of the oil supply to the

burner (i.e., fuel trip):



(3) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches, one


safety shutdown on low pressure


5.7.5.3.2

A complete boiler safety shutdown shall occur if oil is the only fuel being fired.

5.7.5.4 Gas Safety Shutdowns.

5.7.5.4.1

Either of the following conditions shall accomplish a safety shutdown of the gas supply to the burner

(i.e., fuel trip):



5.7.5.4.2

A complete boiler safety shutdown shall occur if gas is the only fuel being fired.

5.7.5.5 Boiler Safety Shutdowns.

Any of the following conditions shall accomplish a complete safety shutdown of the boiler:




(4) Power failure


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(7) The occurrence of either an oil or a gas fuel trip when only that fuel is being fired

5.8 Simultaneous Firing of Oil and Gas for Fuel Transfer Only.

5.8.1* General.

The equipment and procedures of 5.8.1.1 through 5.8.1.4 shall be used to avoid a hazardous

furnace condition when operation of the boiler is transferred from fuel oil to fuel gas or from fuel gas

to fuel oil without requiring a shutdown of the boiler.

5.8.1.1 Simultaneous Firing for Fuel Transfer on a Continuous Basis.

When the combustion control system and the burner management system are both designed for fuel

transfer and simultaneous firing of oil and gas fuels on a continuous basis, the requirements of

Section 5.7 shall apply.

5.8.1.2

Class 1 or Class 2 igniters shall be used during the fuel transfer as required by the manufacturer or

established by test.

5.8.1.3




5.8.1.4



5.8.2 Required Equipment.


(1) A burner that is capable of firing the two fuels simultaneously during the transfer period


(a) Proportioning fuel flow for each fuel individually

(b) Limiting total fuel input to the maximum capacity of the boiler

(c) Controlling a minimum airflow rate

(d) Controlling minimum input rates of each fuel

(e) Providing a stable return to design air-fuel ratio after the trip or shutdown of either fuel

(3) A fuel transfer mode that includes the following:

(a) A gas-firing mode in which oil cannot be fired

(b) An oil-firing mode in which gas cannot be fired


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(c) A gas-oil-firing mode that permits simultaneous firing of both fuels, provided all interlocks

for both fuels are satisfied, including light-off position for both fuel valves

(d) A control device, transfer timer, and an alarm for 5.8.2(3) (c), to limit continuous operation

in this mode



(b) Providesan independent interlock to each fuel being fired that automatically shuts down

the affected fuel with operation continuing on the unaffected fuel in a stable manner; shutdown

of both fuels is permitted

(c) Provides that both the first and second fuels be introduced with their flow control valves in

light-off positions

(d) Provides an interlock action that will trip either fuel should its respective flow control valve

leave a predetermined setting during fuel transfer

(e) Provides for the introduction of the second fuel without requiring a boiler purge

(f) Requires a manual reset following any interlock shutdown

(g) Prohibits the simultaneous light-off of both fuels

(h) Provides detector(s) to supervise any of the following conditions:

(5.8.2(4)(h)1.) Igniter flame as permitted by igniter class

(5.8.2(4)(h)2.) Gas firing

(5.8.2(4)(h)3.) Oil firing

(5.8.2(4)(h)4.) Combined gas and oil firing

(i) Burner flame detectors shall be permitted to supervise multiple fuels.

5.8.3 Simultaneous Firing of Oil and Gas for Fuel Transfer Only (Automated Transfer).

This subsection shall define the requirements and procedures to be used for an automated transfer

of operation from one fuel to a second fuel without requiring a shutdown of the burner.

5.8.3.1 Required Equipment.

Equipment requirements shall be in accordance with 5.8.2 and 5.8.3.1.1 through 5.8.3.1.3 .

5.8.3.1.1

The combustion control system shall have the capability to automatically increase the airflow by a

preset value in response to a fuel transfer signal.

5.8.3.1.2

The airflow shall be held in a fixed position for the transfer period.

5.8.3.1.3


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The fuel transfer mode shall have the capability to signal the combustion control system to increase

airflow and open the safety shutoff valve(s) of the fuel being introduced.


When oil is introduced as the second fuel, the transfer cycle from gas to oil shall be in the following

order:


(2) Install an oil atomizer.

(3) Open the atomizing medium shutoff valve.


(5) Set the gas-firing rate to light-off flow.

(6) Set the oil control valve in the light-off position.

(7) Prove fuel gas and fuel oil control valves are in light-off position.

(8) Gradually increase airflow by a preset amount corresponding to fuel input of fuel oil in light-off.

(9) Establish ignition energy in accordance with the manufacturer's instructions. Where an igniter

is required, see 5.6.2.6.2.2 or 5.6.2.6.2.3 for operating requirements.

(10) Open the oil safety shutoff valves and establish oil flow to the burner.


(12) Select the oil firing mode, which automatically trips the gas safety shutoff valves.

(13) Gradually remove airflow increase.

(14) Return the combustion control system and burner firing rate to automatic operation.



When gas is introduced as the second fuel, the transfer cycle from oil to gas shall be in the following

order:

(1) Establish the gas fuel system to satisfy interlocks.

(2) Select the dual fuel firing mode.

(3) Set the oil-firing rate to light-off flow.

(4) Set the gas control valve to the light-off position.


(6) Increase airflow by a preset amount corresponding to fuel input of fuel gas in light-off.




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to the burner.


(10) Select the gas-firing mode, which automatically trips the oil safety shutoff valves.


(12) Return the combustion control system and burner-firing rate to automatic operation.

(13) Purge the oil gun into furnace, if required.

(14) Close atomizing medium shutoff valve, if required.

(15) Remove oil atomizer, if required.


5.8.4 Simultaneous Firing of Oil and Gas for Fuel Transfer Only (Manual Transfer).

This subsection shall define the requirements and procedures to be used for a manual transfer of

operation from one fuel to a second fuel without requiring a shutdown of the burner.



5.8.4.1.1

The combustion control system shall have the capability to manually adjust the airflow.

5.8.4.1.2

Manual shutoff valves shall be provided at the burner, downstream of the safety shutoff valves for

each fuel.

5.8.4.1.3

A pressure gauge shall be provided in each fuel line downstream of the manual shutoff valve.


When oil is introduced as the second fuel, the procedure to transfer from gas to oil shall be as

follows:

(1) Where a Class 1 or Class 2 igniter is available, place it in service in accordance with the

manufacturer's instructions as required.

(2) Confirm that the manual oil valve at the burner is closed.




(6) Place the combustion control system in manual mode.

(7) Reduce the gas-firing rate to light-off flow.


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(8) Place the oil control valve in the light-off position.

(9) Place the fuel transfer in oil/gas mode, with the following results:

(a) When the oil safety interlocks are satisfied, the oil safety shutoff valves open.

(b) Fuel oil pressure now will be upstream of the manual oil valve at the burner.

(10) Slowly close the manual gas shutoff valve while observing the gas pressure downstream of

the valve until the gas pressure starts to drop. At this point, the gas flow rate is controlled by the

manual valve instead of by the control valve.

(11) Slowly close the manual gas valve while simultaneously opening the manual oil valve to light

the oil flame from the gas flame and proceed as follows:

(a) Continue to increase the oil-firing rate while cutting back on the gas-firing rate to maintain

a constant heat input of the combined fuels to the burner, until the manual gas valve is closed

and the manual oil valve is fully open.

(b) Excess air must be maintained at all times by continuously observing the burner flame or

by observing the air-fuel ratio, oxygen indicator, or opacity indicator, if provided.

(c) During this period, airflow must be maintained at a constant rate with only the manual fuel

valves operated.

(12) Place the fuel transfer mode in the oil position.




When gas is introduced as the second fuel, the procedure to transfer from oil to gas shall be as

follows:


manufacturer's instructions.

(2) Confirm that the manual gas valve at the burner is closed.



(5) Reduce the oil-firing rate to light-off flow.

(6) Place the gas control valve in the light-off position.

(7) Place fuel transfer in the gas/oil mode, with the following results:

(a) When the gas safety interlocks are satisfied, the gas safety shutoff valves open.

(b) Gas pressure now will be upstream of manual gas valve at the burner.

(8) Slowly close the manual oil valve while observing the oil pressure downstream of the valve

until the oil pressure starts to drop. At this point, the oil flow is controlled by the manual valve

instead of by the control valve.


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(9) Slowly close the manual oil valve while simultaneously opening the manual gas valve to light

the gas flame from the oil flame, then proceed as follows:

(a) Continue to increase the gas-firing rate while cutting back on the oil-firing rate to maintain

a constant heat input of the combined fuels to the burner until the manual oil valve is closed

and the manual gas valve is fully open.




valves operated.

(10) Place the fuel transfer mode in the gas position. The oil safety shutoff valves close.


(12) Purge the oil gun into the furnace, if required.


(14) Remove the oil atomizer from burner, if required.

(15) Shut down the igniter as required.

5.8.5 Safety Shutdowns.

Safety shutdowns shall be initiated in accordance with 5.7.5.3 through 5.7.5.5 .

5.9 Dual Oil Atomizers in a Single Burner.

5.9.1* General.

Where a burner is equipped with main and auxiliary oil atomizers for the purpose of changing

atomizers for maintenance without affecting the boiler load, the changeover of atomizers shall be

carried out manually under stable firing conditions by a trained operator.

5.9.1.1



5.9.1.2




5.9.1.3





(1) A burner that is capable of firing two oil atomizers simultaneously during the transfer period


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(2) A combustion control system that is capable of limiting the total fuel input to the maximum

capacity of the boiler and that has the capability to manually adjust the airflow

(3) A safety interlock system in accordance with 5.4.6 that also prohibits the simultaneous light-off

of both atomizers

(4) Manual oil shutoff valves at the burner, downstream of the safety shutoff valves for each

atomizer

(5) A pressure gauge in the fuel line downstream of each manual shutoff valve

(6) Manual atomizing media shutoff valves for each atomizer except on mechanically atomized

systems

5.9.3 Oil Atomizer Changeover Procedure.

The procedures for a manual transfer of operation from one oil atomizer (main or auxiliary) to a

second oil atomizer (auxiliary or main) without requiring a shutdown of the burner shall be as

follows:



(2) Confirm that the manual oil valve at the burner for the atomizer to be started is closed.

(3) Install the second oil atomizer.


(5) Slowly close the manual shutoff valve while observing the oil pressure downstream of the

valve until the oil pressure starts to drop. At this point, the oil flow rate is controlled by the manual

valve instead of by the control valve.

(6) For nonmechanically atomized oil atomizers, slowly open the second atomizing medium

shutoff valve until it is fully open.

(7) Slowly close the manual oil valve for the atomizer in service while simultaneously opening the

manual oil valve of the second atomizer to light the second atomizer from the first and proceed as

follows:

(a) Continue to slowly increase the oil-firing rate on the second atomizer while cutting back

on the firing rate of the first atomizer to maintain a constant heat input of the combined

atomizers until the manual valve of the first atomizer is closed and the manual oil valve of the

second atomizer is fully open.

(b) Excess air shall be maintained at all times by continuous observation of the burner flame

or by observation of the air-fuel ratio, oxygen indicator, or opacity indicator, if provided.


valves operated.

(8) Close the atomizing media shutoff valve on the first atomizer, if present.



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[1] Commented [WG13] Work Group 9/23/2016 7:51:00 AM

Move to Fundamentals Chapter:

4.B.1.9

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the oil line to the main burner.

4.B.1.9.1

Permanent means shall be provided for making manual valve leakage tests of the main burner oil safety shutoff valves.

4.B.1.9.2

Valve leakage tests of the main burner gas safety shutoff valves for all fuels shall be conducted at least annually.

Page 2: [2] Commented [WG14] Work Group 9/23/2016 7:52:00 AM


4.B.1.10

Where pressure can develop in excess of the valve or piping rated pressure(s), the piping design shall include a means to prevent or relieve excess pressure between the valves.



4.B.1.11

Oil piping materials and system design shall be in accordance with NFPA 31 (for oil piping inside industrial or institutional buildings), ASME B31.1, Power Piping (for oil piping in power applications), or ASME B31.3, Process Piping (for oil piping in process applications).




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4.C.2* Fuel Supply — Commercial Grade Fuel Gas.

A.4.C.2

For additional information, see NFPA 54 and NFPA 58.



4.C.2.1

The gas supply at the gas service connection shall be controlled at the pressure for which the fuel-burning system had been designed.



4.C.2.2

Gas piping, valve trains and other components in the system shall be sized to maintain the required pressure over the design firing rate for the burner.



4.C.2.3*

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the fuel gas line to the main burner, and an automatic vent valve shall be provided between the two valves.

A.4.C.2.3

Main burner gas supply. Special precautions are required in locating the vent pipe from the automatic bleed valve so that heavier-than-air, vented gases do not accumulate in depressions or in confined areas. An alternative to the automatic venting of heavier-than-air gases is to eliminate the main vent valve from between the two main safety shutoff valves. See Figure A.4.D.2.3 for a typical main gas burner system arrangement.


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Figure A.4.C.2.3 Typical Fuel Supply Systems and Safety Controls for Gas Burner.



4.C.2.3.1

When a listed automatic valve-proving system is used with two safety shutoff valves in series, each with a proof of closure switch, the automatic vent valve shall be permitted to be omitted.



4.C.2.7.2




4.C.2.7.3

The use of an automatic valve-proving system shall not eliminate the annual leak test required in 4.C.2.7.2 .




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4.D.3 Alternate Fuel Firing.

all be provided to permit operation of the necessary interlocks, fuel safety shutoff valves, and controls for the fuel to be fired.



4.D.3.1 Manual Fuel Selection.

o Where oil and gas are to be burned alternately, a manual fuel selector switch logic in the Burner Management System shall be provided to permit operation of the necessary interlocks, fuel safety shutoff valves, and controls for the fuel to be fired.



4.D.3.2.1

Where oil and gas are to be burned alternately, an automatic change from one fuel to the other shall be accomplished only after a shutdown.



4.D.3.2.2

Provisions for manual changeover of the system shall be provided in accordance with 5.4.3.1 and Section 5.8



4.D.4 Fuel-Burning Equipment.


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4.D.4.1* Ignition.

4.D.1.1


A.4.D.4.1

See Figure A. 4.D.4.1 for typical ignition system arrangements for a gas- or oil-fired burner.

Figure A.4.D.4.1 Typical Ignition Systems for Gas- or Oil-Fired Burner.



4.D.4.1.1.2. Class 2 Igniter

(A) Where a Class 2 igniter is used, it shall not be used to ignite main fuel under uncontrolled or abnormal conditions.

(B) The burner shall be operated under controlled conditions to limit the potential for abnormal operation as well as to limit the charge of fuel to the furnace in the event that ignition does not occur during light-off.


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(C) If the Class 2 igniter is not shut down once the main flame sequence is successfully completed, then the main burner flame shall be

proven by a flame scanner independently of the igniter.



4.D.4.1.1.3 Class 3 Igniter.

(A)* Where a Class 3 igniter is used, the igniter shall be shut down as part of the burner light-off procedure when the time trial for ignition of the main burner has expired.

(B) The use of such igniters to support ignition or to extend the burner control range shall be prohibited.

(C) The main flame shall be proven by a flame scanner.

A.4.D.4.1.1.3(A)

The purpose of this requirement is to ensure that the main flame is self-supporting, is stable, and is not dependent on ignition support from the igniter



4.D.4.1.2

The igniter flame or arc shall impinge on the main burner air-fuel mixture and shall supply ignition energy to provide immediate ignition of all fuel discharge from the main burner under light-off conditions


4.D.4.1.3* Igniter Safety Shutoff Valves.

Two safety shutoff valves in series shall be provided in the fuel gas line to the igniter, and an automatic vent valve shall be provided between the two valves.

A.4.D.4.1.3


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For heavier-than-air gases and gas-fired igniters, many oil-fired boilers are equipped with propane or other liquefied petroleum gas (LP-Gas)–fired igniters. Special precautions are required in locating the vent pipe from the automatic bleed valve so that heavier-than-air, vented gases do not accumulate in depressions or in confined areas. An alternative to the automatic venting of heavier-than-air gases is to eliminate the igniter vent valve from between the two igniter safety shutoff valves. (See Figure A.4.D.4.1)

Figure A.4.D.4.1 Typical Ignition Systems for Gas- or Oil-Fired Burner.



4.D.4.1.3.2*

Where an automatic valve-proving system is installed, valve-proving shall be performed either after every burner shutdown or prior to every burner light-off.

A.4.D.4.1.3.2

It is recommended that valve proving be done at burner shutdown to establish that the gas shutoff valves are tight.


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4.D.4.2.2.2*

The tests shall verify that transients that are generated in the fuel and air systems do not adversely affect burner operation.

A.4.D.4.2.2.2

Such transients are generated by burner control valves, dampers, and other equipment that operate at speeds faster than the speed of response of other components in the system.



4.D.4.2.3

Each manual adjustment feature on the burner shall be provided with means for securing it in its intended position.



4.D.4.2.4

The atomizing equipment for oil burners shall be designed for periodic removal, cleaning, and maintenance.



4.D.4.2.5

Any procedure for clearing the atomizer and piping into the furnace prior to shutdown shall be accomplished while the fan is operating and the igniter is re-established or the main flame is proven continuously during this operation.


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4.D.4.2.6

Clearing of the oil passages of the atomizer into the furnace immediately after a shutdown shall be prohibited.



4.D.4.3.1

Where the fuel is to be atomized with the assistance of another medium, this atomizing medium shall be supplied free of contaminants that could cause an interruption of service.



4.D.4.3.2

The atomizing medium shall be provided at the pressure and temperature specified by the burner manufacturer.



4.D.4.3.3

Provisions shall be made to ensure that fuel cannot enter the atomizing medium line during or after operation.



4.D.4.4.1


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The combustion air supply equipment shall be capable of supplying combustion air for the optimum air-fuel ratio over the entire operating range of the burner.



4.D.4.4.2




4.D.4.4.3




4.D.4.4.3.1

Louvers and grilles shall be fixed in the open position or interlocked with the equipment so that they are opened automatically or manually during equipment operation. The interlock shall be placed on the driven member.



4.D.6.6*

Each safety control ac circuit shall be two wires, one side grounded, and shall be protected with a suitable fuse or circuit breaker in the hot side only.

A.4.D.6.6


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The use of safety control circuit voltages of greater than 120 volts nominal is not recommended.



4.D.6.7.1

Safety control dc circuits shall be arranged as called for in 4.D.6.6 where grounding is possible.



4.D.6.7.2

Where grounding is not possible and the circuit voltage exceeds 50 volts, the circuit shall have switching contacts in one side of the line and shall be provided with ground-fault circuit interrupters.



4.D.7 Flame Safety Shutdown System.

Safety shutoff valves shall meet one of the following requirements:

(1) The safety shutoff valves shall close in 1 second or less upon being de-energized.

(2) Where safety shutoff valve closure time exceeds 1 second, the combined time for safety shutoff valve closure and flame failure response shall not exceed 4 seconds.



4.D.7.3


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Where flame-sensing detectors can fail in the flame-proven mode, self-checking features shall be provided unless the burner is operated for periods less than 24 hours and the burner management system includes a safe-start component checking feature.



4.D.7.4

A safe-start component checking feature shall include a circuit incorporated in the burner management system that prevents light-off if the flame-sensing relay is in the flame-present position due to component failure or due to the presence of actual or simulated flame.



4.D.8.1*


A.4.D.8.1

Locations at which natural gas, propane, or fuel oil systems are installed in compliance with this code normally are not considered hazardous locations for electrical equipment as defined in NFPA 70.



4.D.8.2

Special fuels or applications could require components for hazardous location and shall be reviewed during the design of the system.


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Public Input No. 139-NFPA 85-2016 [ Section No. 5.4.2.3 ]

5.4.2.3*

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the fuel gasline to the main burner, and an automatic vent valve shall be provided between the two valves.

5.4.2.3.1

When a listed automatic valve-proving system is used with The two safety shutoff valves in series, eachwith a proof of closure switch, the automatic vent valve shall be permitted to be omitted. required in 5.4.2.3shall have either an automatic vent valve provided between the two safety shutoff valves or a listed valve-proving system

5.4.2.3.2*

Where automatic valve-proving systems are installed, valve proving shall be performed either after everyburner shutdown or prior to every burner light-off.


Both the vent valve and VPS are equivalent safety devices, and thus both should be in the same paragraph rather than in separate ones.


Submitter Full Name: Kevin Carlisle

Organization: Karl Dungs, Inc.

Street Address:

City:

State:

Zip:

Submittal Date: Fri Dec 16 14:31:59 EST 2016


76 of 372 1/9/2017 1:48 PM


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5.4.6 Interlock System Burner Management System .

5.4.6.1

In addition to the requirements in Section 4.11, the boiler control system for single burner boilers shall bepermitted to be combined with the burner management system under one of the following conditions:

(1)

(2) If the combined boiler control and burner management system is specifically listed or labeled for theapplication; or

(3)

(4)

(5)

5.4.6.2

The system shall be equipped with a method of determining the operating state of each interlock withoutdisassembling any of the interlock devices.

5.4.6.3


5.4.6.4

Interlock devices shall be designed for anticipated environmental conditions, such as temperature, humidity,vibration, and corrosive agents.

5.4.6.5 Bypass.

5.4.6.5.1


5.4.6.5.2


5.4.6.5.3

Interlock devices shall be permitted to be temporarily removed from service for maintenance or testing inaccordance with the following:



5.4.6.5.4

The interlocks on the low water cutouts shall be permitted to be bypassed during normal operation forblowdown purposes only.

5.4.6.5.4.1


* If the fuel-air ratio is controlled externally from the boiler control system; or

* A single safety-rated programmable logic system shall be permitted to be used to implement bothburner management system safety and process logic where both of the following conditions are met:

The processor and input/output (I/O) modules are approved or certified by a notified bodyaccording to IEC 61508, Functional Safety of Electrical/Electronic/Programmable ElectronicSafety-Related Systems , to be at least SIL 3 capable; and

The burner management system logic is isolated from other logic and boiler controls, and therelated data of the burner management system program, including I/O data, are protected frombeing unintentionally affected by data of other user programs.


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5.4.6.6*

Each safety control ac circuit shall be two wires, one side grounded, and shall be protected with a suitablefuse or circuit breaker in the hot side only.


5.4.6.7.1


5.4.6.7.2

Where grounding is not possible and the circuit voltage exceeds 50 volts, the circuit shall have switchingcontacts in one side of the line and shall be provided with ground-fault circuit interrupters.


Note to editor: The only change is to the section 5.4.6 heading. Other paragraphs showing underlining were not affected by this change.

This change revised the section heading from "Interlock System" to "Burner Management System". While the term "interlock" is defined, the term "interlock system" is not defined. The section actually address the "burner management system" which is a defined term. This public input proposed to revise the section heading to reflect the broader scope of the section and to use what appears to be the appropriate defined term.

Related Public Inputs for This Document

Related Input Relationship

Public Input No. 154-NFPA 85-2016 [Section No. 5.7.2]




Submitter Full Name: Richard Gallagher

Organization: Zurich Services Corporation

Street Address:

City:

State:

Zip:

Submittal Date: Tue Dec 20 16:00:32 EST 2016


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5.4.6.2

The system shall be equipped with a method of determining the operating state of each interlock withoutdisassembling any of the devices associated with the interlock devices .






Street Address:

City:

State:

Zip:



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5.4.6.4

Interlock devices Devices associated with the interlocks shall be designed for anticipated environmentalconditions, such as temperature, humidity, vibration, and corrosive agents.






Street Address:

City:

State:

Zip:



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Public Input No. 218-NFPA 85-2017 [ Section No. 5.4.6.5.3 ]

5.4.6.5.3

Interlock devices Interlocks shall be permitted to be temporarily removed from service for maintenance ortesting in accordance with the following:








Street Address:

City:

State:

Zip:



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Public Input No. 180-NFPA 85-2016 [ Sections 5.6, 5.7, 5.8, 5.9 ]

See the attached Word File which contains the formatting changes suggested by the SBB TaskGroup to improve readability, referencing and inderstanding of the document while deletingrepetitive text.

Sections 5.6, 5.7, 5.8, 5.9


5.6.1* General.

This section shall be used to define requirements for automatic recycling and automatic nonrecyclingoperating systems.

5.6.1.1


5.6.1.2

Different arrangements shall be permitted if they provide protection and meet the intent of this code. (SeeFigure A.5.4.1, Figure A.5.4.2.3, and Figure A.5.4.4.1 for typical arrangements.)


5.6.2.1

An automatic (i.e., recycling) unit shall not be started from a cold condition unless a trained operator ispresent.

5.6.2.2

Underlying all the requirements of 5.6.2 shall be the premise that the unit is hot and that steam pressureand operating water level shall have been established.

5.6.2.3


5.6.2.4

The alternate fuel system shall be placed in a nonfiring condition, and the manual burner valve(s) shall beclosed.

5.6.2.5


5.6.2.6

An automatic (i.e., recycling) unit shall recycle on high steam pressure, high water temperature, or lowwater level (not determined by the auxiliary low water cutout) and perform four major functions as given in5.6.2.6.1 through 5.6.2.6.4.4.


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The prefiring cycle shall accomplish the following steps in the listed order, except that the order of steps (5),(6), and (7) in the sequence shall be permitted to vary:



(3) Start the fan.






(9) Air pressure and “open damper” interlocks for all dampers in the flow path

(10) Airflow interlock

(11) Purge airflow must reach no less than 70 percent of the airflow required at maximum continuouscapacity of the unit.

(12) The purge must be for at least eight air changes. Airflow during the period of opening the damper andreturning it to light-off position is permitted to be included in computing the time for eight air changes.



(15) If a flue gas recirculation system is supplied, then it shall be purged per the manufacturer'sinstructions.



The light-off cycle for a burner with a Class 3 igniter shall accomplish the following in the listed order:

(1)

(2) Prove igniter flame within 10 seconds of the energization of the igniter fuel valves; for a Class 3special igniter, proof of igniter operation is not required.

(3) If proven, admit fuel to main burner. For an oil burner other than a return flow type,simultaneously shut off oil-recirculating flow.

(4) If not proven, establish safety shutdown.

(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils, shutoff igniter.

(6) Prove main flame (see 5.4.4.1.1.3 and 5.4.4.1.1.4) and proceed as follows:

(7) If proven, release to modulating control where provided.


* Energize the ignition transformer and igniter fuel valves.


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(1)

(2) Prove igniter flame within 10 seconds of the energization of the igniter fuel valves and proceed asfollows:

(3) If proven, admit fuel to the main burner. For an oil burner other than a return flow type,simultaneously shut off the recirculating flow.


(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils,prove the main flame (see 5.4.4.1.1.2) and proceed as follows:

(6) If proven, release to combustion control for modulation, where provided.




(1)


(3) If proven, admit fuel to the main burner. For an oil burner other than a return flow type,simultaneously shut off recirculating flow.







5.6.2.6.4 Shutdown.


For automatic (i.e., recycling) boilers, high steam pressure, high water temperature, or low water level (notdetermined by the auxiliary low water cutout) shall accomplish a normal shutdown, and the burner shall beallowed to recycle when steam pressure, water temperature, or water level has returned to within the presetoperating range.




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(3) If a Class 1 igniter is used, use the manufacturer's instructions to purge the main burner oil gunprior to continuing the normal shutdown.

(4) Where used, open the recirculating valve.

(5) Shut off atomizing medium, if required by operating procedures.


(7) Perform a postpurge of the furnace and boiler gas passes; the duration of the postpurge must be noless than 15 seconds at an airflow rate not exceeding that at which the unit was shut down.



Any of the conditions in 5.6.2.6.4.3(A) or 5.6.2.6.4.3(B) shall accomplish a safety shutdown, and theburner shall not be allowed to recycle until a trained operator determines the cause of the shutdown andtakes the necessary corrective action to ensure that conditions are within specified operating limits prior torestarting.

(A)







(6) Power failure


(8) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches (one locatedat the service connection and the other at the burner, either one of which shall initiate a safetyshutdown on low pressure)



(B)







(6) Power failure




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The safety shutdown cycle shall accomplish the following in the listed order and shall activate an alarm:





(5) Where used, shut off the atomizing medium, if required by operating procedures.

(6) Where the inerting system is used, energize it simultaneously with 5.6.2.6.4.4(1).

(7) Perform a postpurge of the furnace and boiler gas passes. The duration of the postpurge must be noless than 15 seconds at an airflow rate not exceeding that at which the unit was shut down.



5.6.3 Automatic (Nonrecycling) Systems for Watertube Boilers.

5.6.3.1

The provisions of 5.6.2.1, 5.6.2.3, 5.6.2.5, and 5.6.2.6 shall apply.

5.6.3.2


5.6.3.3

When high steam pressure, high water temperature, or low water level establishes a normal shutdown, theburner shall not be allowed to recycle.

5.6.3.4


5.6.4 Automatic (Recycling) Systems for Firetube Boilers.

5.6.4.1

Underlying all the requirements of 5.6.4 shall be the premise that the equipment is in accordance withSection 5.4, that the boiler has been placed in service in accordance with Section 5.6, and that theoperating water level has been established.

5.6.4.2

An automatic (i.e., recycling) unit shall recycle on high steam pressure, high water temperature, or lowwater level (not determined by the auxiliary low water cutout) and perform four major functions as given in5.6.4.2.1 through 5.6.4.2.4.4(B).


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The prefiring cycle shall accomplish the following steps in the listed order, except that the order of steps5.6.4.2.1(5), 5.6.4.2.1(6), and 5.6.4.2.1(7) in the sequence shall be permitted to vary:



(3) Start the fan.


(5) Where an atomizing medium is used and if not already on, admit the medium to the main burner.




(9) Air pressure and “open damper” interlocks for all dampers in the flow path

(10) Airflow interlock

(11) Purge airflow must reach no less than 70 percent of the airflow required at maximum continuouscapacity of the unit.

(12) The purge of the furnace and boiler gas passes must be for at least four air changes and under thefollowing conditions:

(13) During the purge, the air damper must be driven to the full open position.

(14) Airflow during the time to open the damper and return it to light-off position is permitted to beincluded in computing the time for four air changes.


(16) If a flue gas recirculation system is supplied, then it shall be purged per the manufacturer'sinstructions.



(1)

(2) Prove the igniter flame within 10 seconds of the energization of the igniter fuel valves and proceed asfollows (for a Class 3 special igniter, proof of igniter operation is not required):

(3) If proven, admit fuel to main burner.


(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils, shutoff the igniter.






5.6.4.2.4 Shutdown.



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(4) Where the manufacturer's instructions permit, purging the main burner oil gun in conjunctionwith the operation of its igniter is permitted.





High steam pressure, high water temperature, or low water (not determined by the auxiliary low watercutoff) shall accomplish a normal shutdown, and the burner shall be allowed to recycle when steampressure, water temperature, or water level has returned to within the preset operating range.













Any of the conditions in 5.6.4.2.4.4(A) or 5.6.4.2.4.4(B) shall accomplish a safety shutdown, and theburner shall not be allowed to recycle until a trained operator determines the cause of the shutdown andtakes the necessary corrective action to ensure that conditions are within specified operating limits prior torestarting.


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(A)










(9) Power failure


(B)









(8) Power failure


5.6.5.1


5.6.5.2

When high steam pressure, high water temperature, or low water level establishes a normal shutdown, theburner shall not be allowed to recycle.

5.6.5.3



5.6.6.1


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For oil-fired watertube boilers, the steps listed in Table 5.6.6.1(a) through Table 5.6.6.1(d) shall be takenby a trained operator when starting a manual supervised unit, and the indicated interlocks shall be satisfiedat each step.


Operator Actions * Interlock Functions

(1) Check that fuel safety orsupervisory shutoff valve is closed.

(1) Fuel safety or supervisory shutoff valve is closed.


(3) Where used, open atomizingmedium valve.

(3) Atomizing medium supply is available.

(4) Open damper(s) to purgeposition.

(4) (a) Air pressure and open damper(s) or (b) airflow. [See5.6.2.6.1(9) and 5.6.2.6.1(10).]


(6) Place damper and fuel controlvalve in light-off position.

(6) Damper and fuel control valve are in light-off position. If light-offairflow is less than purge airflow rate, start light-off time limit timer.

(7) None.(7) Spark, igniter, and main safety shutoff valves are ready foroperation.

*In listed order.



(1) Energize ignition transformer and ignitersafety shutoff valves.

(1) Prove igniter flame within 10 seconds ofenergization of igniter fuel valves. (For Class 3 specialigniter, proof of igniter operation is not required.)



(4) Open manual fuel shutoff valve.(4) Prove main flame within 10 seconds for Nos. 2 and4 oils or 15 seconds for Nos. 5 and 6 oils. Close ignitersafety shutoff valve(s).

(5) Bring unit to present operating pressure atrate specified by manufacturer, maintainingair-fuel ratios as established by tests.

(5) None.

(6) On reaching preset pressure range, change toautomatic combustion control.

(6) None.

*In listed order.



(1) Shut off fuel supply to main burner.(1) Fuel safety shutoffvalve(s) to main burner isclosed.




(5) Perform postpurge of furnace and boiler gas passes. Duration ofpostpurge must be no less than 15 seconds at airflow rate not exceedingthat at which unit was shut down.

(5) None.



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*In listed order.



(1) None.(1) Shut off fuel supply to main burner;shut off fuel supply and interrupt spark toigniter, if in operation.

(2) Perform postpurge of furnace and boiler gas passes.Duration of postpurge must be no less than 15 seconds atairflow rate not exceeding that at which unit was shut down.

(2) None.


*In listed order.

5.6.6.1.1

Fuel pressure and temperature, atomizing medium, control system energy, power, and water level shallhave been established.

5.6.6.1.2


5.6.6.2


5.6.6.2.1


5.6.6.2.2


5.6.6.3


5.6.6.4*

Any of the following conditions shall accomplish a safety shutdown, and the burner shall not be restarteduntil a trained operator goes out to the boiler, determines the cause of the shutdown, and takes thenecessary corrective action to ensure that conditions are within specified operating limits prior to restarting:





(5) Power failure




5.6.6.5





5.6.7.1


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For gas-fired watertube boilers, the steps listed in Table 5.6.7.1(a) through Table 5.6.7.1(d) shall be takenby a trained operator when starting a manual supervised unit, and the indicated interlocks shall be satisfiedat each step.



(1) Check that gas safety shutoffvalves are closed.

(1) Gas safety shutoff valves are closed.


(3) Open damper(s) to purgeposition.

(3) (a) Air pressure and open damper(s) or (b) airflow. [See5.6.2.6.1(9) and 5.6.2.6.1(10).]


(5) Place damper and gas controlvalve in light-off position.

(5) Damper and fuel control valve are in light-off position. If light-offairflow is less than purge airflow rate, start light-off time limit timer.

(6) None.(6) Spark and igniter and main safety shutoff valves are ready foroperation.

*In listed order.



(1) Energize ignition transformer and ignitersafety shutoff valve(s).

(1) Prove igniter flame within 10 seconds of theenergization of igniter fuel valves. (For Class 3 specialigniter, proof of igniter operation is not required.)

(2) Open gas safety shutoff valves to mainburner.

(2) Prove main flame is within 10 seconds. Close ignitersafety shutoff valve(s).

(3) Bring unit to preset operating pressure at ratespecified by manufacturer, maintaining air-fuelratios as established by tests.

(3) None.

(4) On reaching preset range, change toautomatic combustion control.

(4) None.

*In listed order.


Operator Actions * InterlockFunctions


(2) Perform postpurge of furnace and boiler gas passes. Duration of postpurge must beno less than 15 seconds at airflow rate not exceeding that at which unit was shut down.

(2) None.


*In listed order.



(1) None.

(1) Shut off gas supply to main burner, shut off fuelsupply, and interrupt spark to igniter, if in operation.Where used, simultaneously energize inertingsystem.

(2) Perform postpurge of furnace and boiler gaspasses. Duration of postpurge must be no less than15 seconds at an airflow rate not exceeding that at

(2) None.


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(3) After postpurge, fan can be permitted to be shutdown.

(3) None.

*In listed order.

5.6.7.1.1


5.6.7.1.2


5.6.7.2


5.6.7.2.1


5.6.7.2.2


5.6.7.3


5.6.7.4

Any of the following conditions shall accomplish a safety shutdown, and the burner shall not be restarteduntil a trained operator goes out to the boiler, determines the cause of the shutdown, and takes thenecessary corrective action to ensure that conditions are within specified operating limits prior to restarting:






(6) Power failure



5.6.8 Soot Blowing.


(1) Soot blowing at nonoptimum air-fuel ratios has been known to lead to explosive formations of air-sootclouds within the boiler and shall be avoided.

(2) Soot blowers shall be operated only while burners are firing at rates such that the burner flame cannotbe extinguished.

(3) Boilers that are equipped with automatic soot-blowing equipment shall have their controls interlockedto prevent operation when the burner is shut down or in the prefiring or light-off cycles.


5.7.1* General.

The equipment and procedures required in 5.7.1.1 through 5.7.1.3 shall be used to avoid a hazardousfurnace condition when firing oil and gas simultaneously in a single burner boiler on a continuous basis.


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5.7.1.1

Class 1 or Class 2 igniters shall be used during the light-off of the second fuel as required by themanufacturer or as established by test.

5.7.1.2

Each boiler shall be tested during initial start-up to determine whether any modifications to the proceduresspecified in Section 5.6 are required to establish ignition or to satisfy other design limitations duringlight-off, warm-up, or normal operation.

5.7.1.3

The initial prefiring cycle, light-off cycle, and normal shutdown cycles for the initial fuel to be fired and forsingle fuel operation shall be completed in accordance with Section 5.6.


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(1) A burner that is capable of burning either oil or gas fuel individually or both fuels simultaneously


(3) Metering and totaling the inputs from both gas and oil fuels alone or in any combination

(4) Proportioning the total fuel input of each fuel individually or in any combination to total airflow inorder to maintain the air-fuel ratio within design limits

(5) Limiting fuel demand to be less than measured airflow and limiting air demand to be greaterthan measured fuel flow

(6) For items 5.7.2(2) (a) through 5.7.2(2) (c), a control system that is designed to accommodatea fixed amount of secondary fuel without metering and totaling all fuels shall be permitted,provided the system maintains air-fuel ratios within design limits throughout the entire operatingrange of the burner

(7) Limiting total fuel input to the maximum capacity of the boiler

(8) Controlling and maintaining a minimum airflow rate that takes into account simultaneous fuelinputs

(9) Controlling and maintaining minimum input rates of each fuel

(10) Requiring a stable return to design air-fuel ratio after the trip or shutdown of either fuel


(12) Meets the requirements of 5.4.6 for each fuel being fired

(13) Requires, on an interlock action specific to only one of the fuels being fired, that this particularfuel automatically shut down with operation continuing on the unaffected fuel in a stable manner;shutdown of both fuels permitted

(14) Requires that both the first and second fuels be introduced with their flow control valves inlight-off positions

(15) Provides for the introduction of the second fuel without requiring a boiler purge

(16) Requires a manual reset following any interlock shutdown

(17) Prohibits the simultaneous light-off of both fuels

(18) Requires flame detector(s) in accordance with 5.4.4 to supervise any of the followingconditions:

(19) Igniter flame as permitted by igniter class

(20) Gas firing

(21) Oil firing

(22) Combined gas and oil firing

(23) Burner flame detectors permitted to supervise multiple fuels


This subsection shall define the requirements and procedures for an automated light-off and subsequentoperation on a continuous basis of a second fuel.


Equipment requirements shall be in accordance with 5.7.2 and 5.7.3.2.


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5.7.3.2





(4) The capability to signal the combustion control system to bias up the airflow, to position the controlvalve for the second fuel to light-off, and to open the safety shutoff valve(s) of the fuel being introduced

(5) The capability to bias up the airflow by a preset value in response to a fuel transfer signal while theairflow remains in automatic mode


When oil is introduced as the second fuel, the light-off cycle for the oil shall accomplish the following in thelisted order:








(8) With airflow in automatic mode, gradually bias up airflow by a preset amount corresponding to fuelinput of fuel oil in light-off.

(9) Establish ignition energy in accordance with manufacturer's instructions. Where an igniter is required,see 5.6.2.6.2, 5.6.2.6.2.2, or 5.6.2.6.2.3 for operating requirements.




(13) Place the combustion control system into the required mode for controlling input rate of each fuel.



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When gas is introduced as the second fuel, the light-off cycle for the gas shall accomplish the following inthe listed order:






(6) With airflow in automatic mode, gradually bias up airflow by a preset amount corresponding to fuelinput of fuel gas in light-off.


(8) Close the vent valve (where used), open the gas safety shutoff valves, and establish gas flow to theburner.






This subsection shall define the requirements and procedures required for the manual light-off andsubsequent operation on a continuous basis of a second fuel.


Equipment requirements shall be in accordance with 5.7.2 and 5.7.4.2.

5.7.4.2

The combustion control system shall have the capability to manually bias up the airflow while the airflowremains in automatic mode.

5.7.4.2.1



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When oil is introduced as the second fuel, the light-off cycle for the oil shall accomplish the following in theorder listed:











(11) Place the combustion control system into the required mode for controlling the input rate of each fuel.








(5) Establish ignition energy in accordance with manufacturer’s instructions. Where an igniter is required,see 5.6.2.6.2, 5.6.2.6.2.2, or 5.6.2.6.2.3 for operating requirements.












(4) Purge oil passages of the oil atomizer.





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5.7.5.3.1

Any of the following operating conditions shall accomplish a safety shutdown of the oil supply to the burner(i.e., fuel trip):



(3) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches, one locatedat the service connection and the other at the burner, either one of which shall initiate a safetyshutdown on low pressure


5.7.5.3.2



5.7.5.4.1

Either of the following conditions shall accomplish a safety shutdown of the gas supply to the burner (i.e.,fuel trip):



5.7.5.4.2







(4) Power failure





5.8.1* General.

The equipment and procedures of 5.8.1.1 through 5.8.1.4 shall be used to avoid a hazardous furnacecondition when operation of the boiler is transferred from fuel oil to fuel gas or from fuel gas to fuel oilwithout requiring a shutdown of the boiler.


When the combustion control system and the burner management system are both designed for fueltransfer and simultaneous firing of oil and gas fuels on a continuous basis, the requirements of Section 5.7shall apply.


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5.8.1.2

Class 1 or Class 2 igniters shall be used during the fuel transfer as required by the manufacturer orestablished by test.

5.8.1.3


5.8.1.4



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(3) Proportioning fuel flow for each fuel individually


(5) Controlling a minimum airflow rate

(6) Controlling minimum input rates of each fuel

(7) Providing a stable return to design air-fuel ratio after the trip or shutdown of either fuel




(11) A gas-oil-firing mode that permits simultaneous firing of both fuels, provided all interlocks forboth fuels are satisfied, including light-off position for both fuel valves

(12) A control device, transfer timer, and an alarm for 5.8.2(3) (c), to limit continuous operation inthis mode



(15) Providesan independent interlock to each fuel being fired that automatically shuts down theaffected fuel with operation continuing on the unaffected fuel in a stable manner; shutdown of bothfuels is permitted

(16) Provides that both the first and second fuels be introduced with their flow control valves inlight-off positions

(17) Provides an interlock action that will trip either fuel should its respective flow control valve leavea predetermined setting during fuel transfer




(21) Provides detector(s) to supervise any of the following conditions:


(23) Gas firing

(24) Oil firing


(26) Burner flame detectors shall be permitted to supervise multiple fuels.

5.8.3 Simultaneous Firing of Oil and Gas for Fuel Transfer Only (Automated Transfer).

This subsection shall define the requirements and procedures to be used for an automated transfer ofoperation from one fuel to a second fuel without requiring a shutdown of the burner.


Equipment requirements shall be in accordance with 5.8.2 and 5.8.3.1.1 through 5.8.3.1.3.


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5.8.3.1.1

The combustion control system shall have the capability to automatically increase the airflow by a presetvalue in response to a fuel transfer signal.

5.8.3.1.2


5.8.3.1.3

The fuel transfer mode shall have the capability to signal the combustion control system to increase airflowand open the safety shutoff valve(s) of the fuel being introduced.


When oil is introduced as the second fuel, the transfer cycle from gas to oil shall be in the following order:









(9) Establish ignition energy in accordance with the manufacturer's instructions. Where an igniter isrequired, see 5.6.2.6.2.2 or 5.6.2.6.2.3 for operating requirements.








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When gas is introduced as the second fuel, the transfer cycle from oil to gas shall be in the following order:







(7) Establish ignition energy in accordance with the manufacturer's instructions. Where an igniter isrequired, see 5.6.2.6.2.2 or 5.6.2.6.2.3 for operating requirements.











This subsection shall define the requirements and procedures to be used for a manual transfer of operationfrom one fuel to a second fuel without requiring a shutdown of the burner.


Equipment requirements shall be in accordance with 5.8.2 and 5.8.4.1.1 through 5.8.4.1.3.

5.8.4.1.1


5.8.4.1.2

Manual shutoff valves shall be provided at the burner, downstream of the safety shutoff valves for each fuel.

5.8.4.1.3



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When oil is introduced as the second fuel, the procedure to transfer from gas to oil shall be as follows:

(1) Where a Class 1 or Class 2 igniter is available, place it in service in accordance with themanufacturer's instructions as required.









(10) When the oil safety interlocks are satisfied, the oil safety shutoff valves open.

(11) Fuel oil pressure now will be upstream of the manual oil valve at the burner.

(12) Slowly close the manual gas shutoff valve while observing the gas pressure downstream of the valveuntil the gas pressure starts to drop. At this point, the gas flow rate is controlled by the manual valveinstead of by the control valve.

(13) Slowly close the manual gas valve while simultaneously opening the manual oil valve to light the oilflame from the gas flame and proceed as follows:

(14) Continue to increase the oil-firing rate while cutting back on the gas-firing rate to maintain aconstant heat input of the combined fuels to the burner, until the manual gas valve is closed andthe manual oil valve is fully open.

(15) Excess air must be maintained at all times by continuously observing the burner flame or byobserving the air-fuel ratio, oxygen indicator, or opacity indicator, if provided.

(16) During this period, airflow must be maintained at a constant rate with only the manual fuelvalves operated.





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When gas is introduced as the second fuel, the procedure to transfer from oil to gas shall be as follows:

(1) Where a Class 1 or Class 2 igniter is available, place it in service in accordance with themanufacturer's instructions.







(8) When the gas safety interlocks are satisfied, the gas safety shutoff valves open.

(9) Gas pressure now will be upstream of manual gas valve at the burner.

(10) Slowly close the manual oil valve while observing the oil pressure downstream of the valve until the oilpressure starts to drop. At this point, the oil flow is controlled by the manual valve instead of by thecontrol valve.

(11) Slowly close the manual oil valve while simultaneously opening the manual gas valve to light the gasflame from the oil flame, then proceed as follows:

(12) Continue to increase the gas-firing rate while cutting back on the oil-firing rate to maintain aconstant heat input of the combined fuels to the burner until the manual oil valve is closed and themanual gas valve is fully open.










Safety shutdowns shall be initiated in accordance with 5.7.5.3 through 5.7.5.5.


5.9.1* General.

Where a burner is equipped with main and auxiliary oil atomizers for the purpose of changing atomizers formaintenance without affecting the boiler load, the changeover of atomizers shall be carried out manuallyunder stable firing conditions by a trained operator.

5.9.1.1

Class 1 or Class 2 igniters shall be used during the fuel transfer as required by the manufacturer orestablished by test.

5.9.1.2



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5.9.1.3





(2) A combustion control system that is capable of limiting the total fuel input to the maximum capacity ofthe boiler and that has the capability to manually adjust the airflow

(3) A safety interlock system in accordance with 5.4.6 that also prohibits the simultaneous light-off of bothatomizers

(4) Manual oil shutoff valves at the burner, downstream of the safety shutoff valves for each atomizer


(6) Manual atomizing media shutoff valves for each atomizer except on mechanically atomized systems


The procedures for a manual transfer of operation from one oil atomizer (main or auxiliary) to a second oilatomizer (auxiliary or main) without requiring a shutdown of the burner shall be as follows:





(5) Slowly close the manual shutoff valve while observing the oil pressure downstream of the valve untilthe oil pressure starts to drop. At this point, the oil flow rate is controlled by the manual valve instead ofby the control valve.

(6) For nonmechanically atomized oil atomizers, slowly open the second atomizing medium shutoff valveuntil it is fully open.

(7) Slowly close the manual oil valve for the atomizer in service while simultaneously opening the manualoil valve of the second atomizer to light the second atomizer from the first and proceed as follows:

(8) Continue to slowly increase the oil-firing rate on the second atomizer while cutting back on thefiring rate of the first atomizer to maintain a constant heat input of the combined atomizers untilthe manual valve of the first atomizer is closed and the manual oil valve of the second atomizer isfully open.

(9) Excess air shall be maintained at all times by continuous observation of the burner flame or byobservation of the air-fuel ratio, oxygen indicator, or opacity indicator, if provided.







NFPA_85-2015_Chapter_5_Working_Copy_29Sep2016.docxReformatted text for Sections 5.6-5.9 done by the SBB Task Group


106 of 372 1/9/2017 1:48 PM


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This reformatting of sections 5.6 through 5.9 standardize the format used and eliminates the tables previously used in 5.6. It also eliminates repetition of text by combining similar procedures used for both water-tube or Firetube Boilers.


Submitter Full Name: John Eibl

Organization: The Chemours Company Inc.

Affilliation: NFPA 85 SBB Task Group

Street Address:

City:

State:

Zip:

Submittal Date: Sat Dec 24 13:16:45 EST 2016


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Chapter 5 Single Burner Boilers

5.1 Application.

5.1.1

This chapter shall be used in conjunction with Chapters 1 through 4 and requires the coordination of

operation procedures, control systems, interlocks, and structural design.

5.1.2

Where conflicts exist, the requirements of Chapter 5 shall apply.

5.1.3

All safety shutoff valves, safety interlock devices, valve-proving systems, and flame detection

systems shall be listed or approved. A safety shutoff valve proof of closure switch shall be an

original design component of the valve or actuator assembly and shall activate only after the valve is

fully closed.

5.2 Purpose.

The purpose of this chapter shall be to establish minimum requirements for the design, installation,

operation, and maintenance of single burner boilers, their fuel-burning systems, and related systems

to contribute to operation within design limits and, in particular, to the prevention of furnace

explosions.

5.3 Unattended Operation.

The process hazard analysis required by 4.1.4 shall not apply to automatic recycling and automatic

nonrecycling single burner boilers designed for unattended operation unless required by the

authority having jurisdiction.



5.4.1.1

Fuel shall be stored, prepared, and delivered to the oil service connection under anticipated

operating conditions in accordance with the applicable portions of NFPA 31.

5.4.1.2


5.4.1.3

Fuel shall be delivered continuously to the combustion chamber in a finely atomized form that can

be ignited readily and consumed.

5.4.1.4

All equipment that is associated with pumping, heating, and straining the fuel from storage to the

service connection shall be designed, sized, and interconnected so as to provide a fuel supply that

meets the boiler design requirements over a full range of conditions.

Original 2015 Text with Formatting changes only


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5.4.1.5


5.4.1.6

Fuel being burned shall be delivered to the burner at the temperature and pressure specified by the

burner manufacturer.

5.4.1.7

Where the fuel must be heated, the interlocks and instruments shall reflect the correct values of the

variable being measured, particularly in dead-end lines, where heavy oil will tend to solidify.

5.4.1.8 Oil Supply.

5.4.1.8.1

The operation of a burner system that has the capability to burn heated and unheated oils shall

include a procedure to ensure that the specified grade of oil, compatible with the selected mode of

operation, is being supplied to the burner.

5.4.1.8.2


5.4.1.9

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the oil

line to the main burner.

5.4.1.10

Where pressure can develop in excess of the valve or piping rated pressure(s), the piping design

shall include a means to prevent or relieve excess pressure between the valves.

5.4.1.11

Oil piping materials and system design shall be in accordance with NFPA 31 (for oil piping inside

industrial or institutional buildings), ASME B31.1, Power Piping (for oil piping in power applications),

or ASME B31.3, Process Piping (for oil piping in process applications).


5.4.2.1

The gas supply at the gas service connection shall be controlled at the pressure for which the fuel-

burning system had been designed.

5.4.2.2


5.4.2.3*

Two safety shutoff valves in series, each with a proof of closure switch, shall be provided in the fuel

gas line to the main burner, and an automatic vent valve shall be provided between the two valves.


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5.4.2.3.1

When a listed automatic valve-proving system is used with two safety shutoff valves in series, each

with a proof of closure switch, the automatic vent valve shall be permitted to be omitted.

5.4.2.3.2*

Where automatic valve-proving systems are installed, valve proving shall be performed either after


5.4.2.4

Foreign matter such as welding beads, chips, scale, dust, and debris shall be removed from the gas

piping.

5.4.2.5


5.4.2.6

Gas piping material and system design shall be in accordance with NFPA 54 (for gas piping inside

industrial and institutional buildings), ASME B31.1, Power Piping (for gas piping in power

applications), or ASME B31.3, Process Piping (for gas piping in process applications).


5.4.2.7.1

Permanent means shall be provided for making manual valve leakage tests of the main burner gas


5.4.2.7.2


5.4.2.7.3

The use of an automatic valve-proving system shall not eliminate the annual leak test required in

5.4.2.7.2.



Where oil and gas are to be burned alternately, a manual fuel selector switch shall be provided to

permit operation of the necessary interlocks, fuel safety shutoff valves, and controls for the fuel to be

fired.


5.4.3.2.1

Where oil and gas are to be burned alternately, an automatic change from one fuel to the other shall

be accomplished only after a shutdown.

5.4.3.2.2


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Provisions for manual changeover of the system shall be provided in accordance with 5.4.3.1 and

Section 5.8 .

5.4.3.2.3



5.4.4.1* Ignition.

5.4.4.1.1



(A)


(B)



(A)

Where a Class 2 igniter is used, it shall not be used to ignite main fuel under uncontrolled or

abnormal conditions.

(B)

The burner shall be operated under controlled conditions to limit the potential for abnormal operation

as well as to limit the charge of fuel to the furnace in the event that ignition does not occur during

light-off.

(C)

If the Class 2 igniter is not shut down once the main flame sequence is successfully completed, then

the main burner flame shall be proven by a flame scanner independently of the igniter.


(A)*

Where a Class 3 igniter is used, the igniter shall be shut down as part of the burner light-off

procedure when the time trial for ignition of the main burner has expired.

(B)


(C)




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5.4.4.1.2

The igniter flame or arc shall impinge on the main burner air-fuel mixture and shall supply ignition

energy to provide immediate ignition of all fuel discharge from the main burner under light-off

conditions.


Two safety shutoff valves in series shall be provided in the fuel gas line to the igniter, and an

automatic vent valve shall be provided between the two valves.

5.4.4.1.3.1

When a listed automatic valve-proving system is used with two safety shutoff valves in series, the

automatic vent valve shall be permitted to be omitted.

5.4.4.1.3.2*

Where an automatic valve-proving system is installed, valve-proving shall be performed either after


5.4.4.1.4



5.4.4.2.1

The main burner shall direct the fuel and air into the furnace so as to provide a stable flame and

efficient combustion over its entire operating range.

5.4.4.2.2


5.4.4.2.2.1

These tests shall be performed without the igniter in service and shall include the intended range

and grade of fuel(s).

5.4.4.2.2.2*

The tests shall verify that transients that are generated in the fuel and air systems do not adversely

affect burner operation.

5.4.4.2.3

Each manual adjustment feature on the burner shall be provided with means for securing it in its

intended position.

5.4.4.2.4

The atomizing equipment for oil burners shall be designed for periodic removal, cleaning, and

maintenance.


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5.4.4.2.5

Any procedure for clearing the atomizer and piping into the furnace prior to shutdown shall be

accomplished while the fan is operating and the igniter is re-established or the main flame is proven

continuously during this operation.

5.4.4.2.6

Clearing of the oil passages of the atomizer into the furnace immediately after a shutdown shall be

prohibited.


5.4.4.3.1

Where the fuel is to be atomized with the assistance of another medium, this atomizing medium

shall be supplied free of contaminants that could cause an interruption of service.

5.4.4.3.2

The atomizing medium shall be provided at the pressure and temperature specified by the burner

manufacturer.

5.4.4.3.3

Provisions shall be made to ensure that fuel cannot enter the atomizing medium line during or after

operation.


5.4.4.4.1

The combustion air supply equipment shall be capable of supplying combustion air for the optimum

air-fuel ratio over the entire operating range of the burner.

5.4.4.4.2


5.4.4.4.3

The requirements for the availability of combustion air shall be determined from NFPA 31 and NFPA

54.

5.4.4.4.3.1

Louvers and grilles shall be fixed in the open position or interlocked with the equipment so that they

are opened automatically or manually during equipment operation. The interlock shall be placed on

the driven member.

5.4.4.4.3.2

Fans supplying air to the boiler room for combustion shall be interlocked with the burner so that

airflow is proven during equipment operation.

5.4.4.5 Furnace.


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The furnace shall be designed to promote main burner stability while minimizing zones that cannot

be purged.


5.4.4.6.1*

The outlet draft equipment shall be capable of removing combustion products without adversely

affecting stable flame conditions.

5.4.4.6.2

Where two or more boilers are connected to a common stack, each connection shall be equipped

with a damper system.

5.4.4.6.2.1


5.4.4.6.2.2


5.4.4.6.2.3


5.4.4.6.2.4

To prevent the interlock from being rendered nonfunctional if the linkage becomes disconnected,

one of the following means shall be provided:




5.4.4.6.2.5

Dampers shall not be required on the outlet of boilers of a type in which maintenance operations are

performed from outside the boiler.

5.4.4.6.3*

Permanently installed flue gas analyzers shall not present an ignition source hazard to the flue gas

stream being sampled.


5.4.5.1


5.4.5.2

The combustion control system shall maintain air-fuel mixtures at pre-established ratios throughout

the operating range of the burner and during changes in the firing rate.


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5.4.5.3*

The system shall provide limits on fuel and air to prevent furnace input from being reduced below

the point of stable burner operation.

5.4.5.4

The minimum and maximum points of stable burner operation shall be defined by the burner

manufacturer and verified by operational tests.


5.4.6.1

In addition to the requirements in Section 4.11, the boiler control system for single burner boilers

shall be permitted to be combined with the burner management system under one of the following

conditions:

(1) *If the fuel-air ratio is controlled externally from the boiler control system; or

(2) If the combined boiler control and burner management system is specifically listed or labeled

for the application; or

(3) *A single safety-rated programmable logic system shall be permitted to be used to implement

both burner management system safety and process logic where both of the following conditions

are met:

(a) The processor and input/output (I/O) modules are approved or certified by a notified body

according to IEC 61508, Functional Safety of Electrical/Electronic/Programmable Electronic

Safety-Related Systems, to be at least SIL 3 capable; and

(b) The burner management system logic is isolated from other logic and boiler controls, and

the related data of the burner management system program, including I/O data, are protected

from being unintentionally affected by data of other user programs.

5.4.6.2

The system shall be equipped with a method of determining the operating state of each interlock

without disassembling any of the interlock devices.

5.4.6.3


5.4.6.4

Interlock devices shall be designed for anticipated environmental conditions, such as temperature,

humidity, vibration, and corrosive agents.

5.4.6.5 Bypass.

5.4.6.5.1


5.4.6.5.2


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5.4.6.5.3

Interlock devices shall be permitted to be temporarily removed from service for maintenance or

testing in accordance with the following:

(1) Removal of the interlock shall be authorized by a competent person and documented in

accordance with operating procedures.

(2) Alternate means shall be substituted to supervise this interlock function in accordance with

operating procedures.

5.4.6.5.4

The interlocks on the low water cutouts shall be permitted to be bypassed during normal operation

for blowdown purposes only.

5.4.6.5.4.1


5.4.6.6*

Each safety control ac circuit shall be two wires, one side grounded, and shall be protected with a

suitable fuse or circuit breaker in the hot side only.


5.4.6.7.1


5.4.6.7.2

Where grounding is not possible and the circuit voltage exceeds 50 volts, the circuit shall have

switching contacts in one side of the line and shall be provided with ground-fault circuit interrupters.


5.4.7.1

The response time from flame failure to de-energization of the safety shutoff valves shall not exceed

4 seconds.

5.4.7.2

The response time from de-energization of the safety shutoff valves to full closure shall not exceed 1

second.

5.4.7.3

Where flame-sensing detectors can fail in the flame-proven mode, self-checking features shall be

provided unless the burner is operated for periods less than 24 hours and the burner management

system includes a safe-start component checking feature.

5.4.7.4


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A safe-start component checking feature shall include a circuit incorporated in the burner

management system that prevents light-off if the flame-sensing relay is in the flame-present position

due to component failure or due to the presence of actual or simulated flame.


5.4.8.1*


5.4.8.2

Special fuels or applications could require components for hazardous location and shall be reviewed

during the design of the system.


Systems installed or designed to reduce NOx emissions shall be evaluated to ensure that the

performance of flame safety and combustion control systems are not impaired.

5.5 Starting of a Cold Boiler.

5.5.1 General.

5.5.1.1

Starting of a cold boiler shall be accomplished in conformance with the manufacturer's

recommendations.

5.5.1.2

In no case shall a boiler that has been taken out of service for maintenance, repair, or extended

shutdown be started from a cold condition without a trained operator present.

5.5.1.3 Start-Up Procedures.

5.5.1.3.1

Applicable start-up procedures for the provided boiler shall be followed.

5.5.1.3.2

The firing rate shall be limited in accordance with the boiler manufacturer's instructions.

5.5.2 Gas-Fired Boilers.

The procedures of Section 5.6 shall be followed for starting a cold gas-fired boiler.

5.5.3 Oil-Fired Burners.

When steam is not available for heating oil, as an atomizing medium, or for driving auxiliary

equipment, one of the starting methods described in 5.5.3.1 , 5.5.3.2 , or 5.5.3.3 shall be used.

5.5.3.1 Auxiliary Air Atomizing of Oil.

When auxiliary air atomizing of oil is used for a cold start-up, all the equipment, facilities, and

procedures listed in 5.5.3.1.1 , 5.5.3.1.2 , and 5.5.3.1.3 shall be required.



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(1) Forced draft (FD) fan


minimum fire with stable flame (only for fuel oils that require heating)

(3) Check valves in steam and air lines to the atomizer

5.5.3.1.2* Required Facility.

An alternate atomizing air supply shall be required.



(1) Circulate and heat oil, using auxiliary heater and recirculating system, to satisfy all interlocks,

where included.

(2) Follow the prefiring and light-off cycles as described in Section 5.6 , using air as the atomizing

medium.



down in accordance with the normal shutdown procedure described in Section 5.6 .

(5) Close the atomizing air supply and open the atomizing steam supply, making certain that dry

steam is available.



5.5.3.2 Auxiliary Mechanical Atomizing of Heavy Oil.

When auxiliary mechanical atomizing of heavy oil is used for a cold start-up, all the equipment,

facilities, and procedures in 5.5.3.2.1 and 5.5.3.2.2 shall be required.


The following equipment and facilities shall be required:

(1) FD fan.


minimum fire with stable flame.







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(1) Circulate and heat oil using auxiliary heater and recirculating systems to satisfy oil interlocks,

where included.

(2) Bypass atomizing medium interlocks. [See 5.5.3.2.1(4) .]

(3) Insert mechanical atomizer.

(4) Follow the prefiring and light-off cycles as described in Section 5.6 .



down in accordance with the normal shutdown procedure as described in Section 5.6 .



(9) Make the atomizing medium interlocks operable and place into service.



5.5.3.3 Auxiliary Mechanical Atomizing of Light (Unheated) Oil.

When auxiliary mechanical atomizing of light (unheated) oil is used for a cold start-up, all the

equipment, facilities, and procedures in 5.5.3.3.1 through 5.5.3.3.3 shall be required.



(1) FD fan.


(3) Check valves in the heavy and light oil lines.



5.5.3.3.2 Required Facility.

A light oil supply shall be required.



(1) Shut off heavy oil to the system.

(2) Insert the mechanical atomizer.

(3) Bypass heavy oil and atomizing medium interlocks. [See 5.5.3.3.1(4) .]

(4) Open the light oil supply into the system.

(5) Follow prefiring and light-off cycles described in Section 5.6 .


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(6) Set combustion control at the light-off rate.

(7) When steam pressure has reached the point required for heating and atomizing the heavy oil,

shut down in accordance with the normal shutdown procedure as described in Section 5.6 .

(8) Shut off the light oil supply to the system.



(11) Make the heavy oil and atomizing medium interlocks operable by removing bypasses.

(12) Open the heavy oil supply to the system.



5.6.1* General.

This section shall be used to define requirements for automatic recycling, and automatic

nonrecycling operating systems and manual supervised burner management systems.

5.6.1.1


5.6.1.2

Different arrangements shall be permitted if they provide protection and meet the intent of this code.

(See Figure A.5.4.1, Figure A.5.4.2.3, and Figure A.5.4.4.1 for typical arrangements.)


5.6.2.1

An automatic (i.e., recycling) unit shall not be started from a cold condition unless a trained operator

is present. See section 5.5 for instructions on starting of a Cold Boiler

5.6.2.2

Underlying all the requirements of 5.6.2 shall be the premise that the unit is hot and that steam

pressure and operating water level shall have been established.

5.6.2.3


5.6.2.4

The alternate fuel system shall be placed in a nonfiring condition, and the manual burner valve(s)

shall be closed.

5.6.2.5


5.6.2.6

Commented [EJJ1]: Standardizing requirements throughout the section and the formatting . Team agrees.

Commented [EJJ2]: Will need to check reference numbers

Commented [EJJ3]: Combining both firetube & watertube sections for standardization. Team agrees.


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as given in 5.6.2.6.1 through 5.6.2.6.4.4 .



steps (5), (6), and (7) in the sequence shall be permitted to vary:



(3) Start the fan.










(10) The purge must be for at least eight air changes. During the purge, the air dampers must be

driven to their full open positions. Airflow during the period of opening the damperdampers and

returning themit to light-off position is permitted to be included in computing the time for eight air

changes the purge.

(a) For Watertube Boilers, the purge must be for at least eight air changes of the furnace

and gas passes.

(b) For Firetube Boilers, the purge must be for at least four air changes of the furnace

and gas passes.




instructions.




order:


Commented [DB4]: Combine purge requirements for water tube and fire tube boilers.

Commented [DB5]: Consider rewording to “positions corresponding to the maximum continuous capacity of the unit”.

Formatted: Indent: Left: 0.72"

Formatted: Indent: Left: 0.72", Space Before: 0 pt


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(2) Prove igniter flame within 10 seconds of the energization of the igniter fuel valves; for a Class

3 special igniter, proof of igniter operation is not required.

(a) If proven, admit fuel to main burner. For an oil burner other than a return flow type,

simultaneously shut off oil-recirculating flow.



oils, shut off igniter.






order:



as follows:


simultaneously shut off the recirculating flow.








order:



as follows:


simultaneously shut off recirculating flow.






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5.6.2.6.4 Shutdown.


For automatic (i.e., recycling) boilers, high steam pressure, high water temperature, or low water

level (not determined by the auxiliary low water cutout) shall accomplish a normal shutdown, and the

burner shall be allowed to recycle when steam pressure, water temperature, or water level has

returned to within the preset operating range.





(a) IfFor watertube boilers, Iif a Class 1 igniter is used, use the manufacturer's instructions to

purge the main burner oil gun prior to continuing the normal shutdown. For firetube boilers,

where the manufacturer’s instructions permit, purging the main burner oil gun in conjunction

with the operation of its igniter is permitted.

(b) Where used, open the recirculating valve.

(c) ShutWhere used, Sshut off atomizing medium, if required by operating procedures.


(4) Perform a postpurge of the furnace and boiler gas passes; the duration of the postpurge must








(A)






Commented [DB6]: Combine unique requirements of firetube boilers into watertube section


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(6) Power failure


(8) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches (one


safety shutdown on low pressure)



(B)







(6) Power failure




The safety shutdown cycle shall accomplish the following in the listed order and shall activate an

alarm:











5.6.3 Automatic (Nonrecycling) Systems for Watertube Boilers. Commented [DB7]: Applies to both watertube and firetube boilers


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5.6.3.1

The provisions of 5.6.2.1 , 5.6.2.3 , 5.6.2.5 , and 5.6.2.6 shall apply.

5.6.3.2


5.6.3.3



5.6.3.4


5.6.4 Automatic (Recycling) Systems for Firetube BoilersManual Supervised Burner

Management Systems.

5.6.4.1

Underlying all the requirements of 5.6.4 shall be the premise that the equipment is in accordance

with Section 5.4 , that the boiler has been placed in service in accordance with Section 5.6 , and that

the operating water level has been establishedThe provisions of 5.6.2 shall apply. The steps listed

shall be taken by a trained operator when starting a manual supervised unit, and the

reaquiredrequired interlocks shall be satisfied at each step.

5.6.4.2

An automatic (i.e., recycling) unit shall recycle on high steam pressure, high water

temperature, or low water level (not determined by the auxiliary low water cutout) and perform

four major functions as given in 5.6.4.2.1 through 5.6.4.2.4.4(B) Fuel pressure and

temperature, atomizing medium, control system energy, power, and water level shall have

been established.

5.6.4.3


5.6.4.4

The provisions of of 5.6.2.6.4.1 shall not apply

5.6.4.5




Commented [DB8]: Firetube requirements moved to watertube section

Commented [DB9]: Section replaces table format for manual supervised systems.

Commented [DB10]: Incorporated into watertube section

Commented [DB11]: Tabular format should be reviewed to insure intent is retained in this new format.

Formatted: Space After: 0 pt

Commented [DB12]: Incorporated into watertube section

Formatted: Font: Bold




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steps 5.6.4.2.1(5), 5.6.4.2.1(6), and 5.6.4.2.1(7) in the sequence shall be permitted to vary:



(3) Start the fan.


(5) Where an atomizing medium is used and if not already on, admit the medium to the main

burner.








(10) The purge of the furnace and boiler gas passes must be for at least four air changes and

under the following conditions:

(a) During the purge, the air damper must be driven to the full open position.

(b) Airflow during the time to open the damper and return it to light-off position is permitted to

be included in computing the time for four air changes.



instructions.




(2) Prove the igniter flame within 10 seconds of the energization of the igniter fuel valves and

proceed as follows (for a Class 3 special igniter, proof of igniter operation is not required):




oils, shut off the igniter.




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5.6.4.2.4 Shutdown.






(b) Where the manufacturer's instructions permit, purging the main burner oil gun in

conjunction with the operation of its igniter is permitted.

(c) Where used, shut off the atomizing medium, if required by operating procedures.





High steam pressure, high water temperature, or low water (not determined by the auxiliary low

water cutoff) shall accomplish a normal shutdown, and the burner shall be allowed to recycle when

steam pressure, water temperature, or water level has returned to within the preset operating range.















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(A)










(9) Power failure


(B)









(8) Power failure


5.6.5.1


5.6.5.2




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5.6.5.3



5.6.6.1

For oil-fired watertube boilers, the steps listed in Table 5.6.6.1(a) through Table 5.6.6.1(d) shall be





(1) Check that fuel safety or

supervisory shutoff valve is closed. (1) Fuel safety or supervisory shutoff valve is closed.


(3) Where used, open atomizing

medium valve. (3) Atomizing medium supply is available.


position.


5.6.2.6.1(9) and 5.6.2.6.1(10).]


(6) Place damper and fuel control

valve in light-off position.



(7) None. (7) Spark, igniter, and main safety shutoff valves are ready for

operation.

*In listed order.





(1) Prove igniter flame within 10 seconds of





(4) Open manual fuel shutoff valve.

(4) Prove main flame within 10 seconds for Nos. 2

and 4 oils or 15 seconds for Nos. 5 and 6 oils. Close


(5) Bring unit to present operating pressure at



(5) None.

Commented [DB13]: Common with watertube section, incorporated into watertube section.

Commented [DB14]: Manual supervised tabular format intent nearly identical to combined watertube and firetube section, revised to reference watertube section and list specific differences in requirements.


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(6) On reaching preset pressure range, change

to automatic combustion control. (6) None.

*In listed order.



(1) Shut off fuel supply to main burner.

(1) Fuel safety shutoff

valve(s) to main burner is

closed.




(5) Perform postpurge of furnace and boiler gas passes. Duration of

postpurge must be no less than 15 seconds at airflow rate not exceeding

that at which unit was shut down.

(5) None.


*In listed order.



(1) None.

(1) Shut off fuel supply to main burner;

shut off fuel supply and interrupt spark

to igniter, if in operation.

(2) Perform postpurge of furnace and boiler gas passes.

Duration of postpurge must be no less than 15 seconds at

airflow rate not exceeding that at which unit was shut down.

(2) None.


*In listed order.

5.6.6.1.1

Fuel pressure and temperature, atomizing medium, control system energy, power, and water level

shall have been established.

5.6.6.1.2


5.6.6.2


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5.6.6.2.1


5.6.6.2.2


5.6.6.3


5.6.6.4*









(5) Power failure




5.6.6.5





5.6.7.1

For gas-fired watertube boilers, the steps listed in Table 5.6.7.1(a) through Table 5.6.7.1(d) shall be





(1) Check that gas safety shutoff

valves are closed. (1) Gas safety shutoff valves are closed.


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position.


5.6.2.6.1(9) and 5.6.2.6.1(10).]


(5) Place damper and gas

control valve in light-off position.



(6) None. (6) Spark and igniter and main safety shutoff valves are ready for

operation.

*In listed order.




safety shutoff valve(s).

(1) Prove igniter flame within 10 seconds of the



(2) Open gas safety shutoff valves to main

burner.

(2) Prove main flame is within 10 seconds. Close


(3) Bring unit to preset operating pressure at



(3) None.

(4) On reaching preset range, change to

automatic combustion control. (4) None.

*In listed order.


Operator Actions* Interlock

Functions


(2) Perform postpurge of furnace and boiler gas passes. Duration of postpurge must be

no less than 15 seconds at airflow rate not exceeding that at which unit was shut down. (2) None.


*In listed order.




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(1) None.

(1) Shut off gas supply to main burner, shut off

fuel supply, and interrupt spark to igniter, if in

operation. Where used, simultaneously energize

inerting system.

(2) Perform postpurge of furnace and boiler gas

passes. Duration of postpurge must be no less than

15 seconds at an airflow rate not exceeding that at


(2) None.

(3) After postpurge, fan can be permitted to be shut

down. (3) None.

*In listed order.

5.6.7.1.1


5.6.7.1.2


5.6.7.2


5.6.7.2.1


5.6.7.2.2


5.6.7.3


5.6.7.4











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(6) Power failure



5.6.85 Soot Blowing.


(1) Soot blowing at nonoptimum air-fuel ratios has been known to lead to explosive formations of

air-soot clouds within the boiler and shall be avoided.

(2) Soot blowers shall be operated only while burners are firing at rates such that the burner flame

cannot be extinguished.

(3) Boilers that are equipped with automatic soot-blowing equipment shall have their controls

interlocked to prevent operation when the burner is shut down or in the prefiring or light-off cycles.


5.7.1* General.

The equipment and procedures required in 5.7.1.1 through 5.7.1.3 shall be used to avoid a

hazardous furnace condition when firing oil and gas simultaneously in a single burner boiler on a

continuous basis.

5.7.1.31



5.7.1.1 2

Class 1 or Class 2 iIgnitersigniters shall be used during the light-off of the second fuel as required by

the manufacturer or and as established by test.

5.7.1.2 3




5.7.1.3





(1) A burner that is capable of burning either fuel oil or fuel gas fuel individually or both fuels

simultaneously


Commented [TJ15]: On 1/30 our discussion was that “on a continuous basis” implies not being at low fire when transferring between fuels. My suggestion is to delete it.

Commented [TJ16]: Relocation as suggested by the group on 1/30/

Formatted: Indent: Left: 0.33", Right: 0.33"

Commented [TJ17]: My suggestion is to not restrict the use of any igniter that is recommended by the manufacturer and proven by test.


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(a) Metering and totaling the inputs from both gas and oil fuels alone or in any combination

(b) Proportioning the total fuel input of each fuel individually or in any combination to total

airflow in order to maintain the air-fuel ratio within design limits

(c) Limiting fuel demand to be less than measured airflow and limiting air demand to be

greater than measured fuel flow

(d) For items 5.7.2(2) (a) through 5.7.2(2) (c), a control system that is designed to

accommodate a fixed amount of secondary fuel without metering and totaling all fuels shall be

permitted, provided the system maintains air-fuel ratios within design limits throughout the

entire operating range of the burner

(e) Limiting total fuel input to the maximum capacity of the boiler

(f) Controlling and maintaining a minimum airflow rate that takes into account simultaneous

fuel inputs

(g) Controlling and maintaining minimum input rates of each fuel

(h) Requiring a stable return to design air-fuel ratio after the trip or shutdown of either fuel



(b) Requires, on an interlock action specific to only one of the fuels being fired, that this

particular fuel automatically shut down with operation continuing on the unaffected fuel in a

stable manner; shutdown of both fuels permitted

(c) Requires that both the first and second fuels be introduced with their flow control valves in

light-off positions

(d) Provides for the introduction of the second fuel without requiring a boiler purge

(e) Requires a manual reset following any interlock shutdown

(f) Prohibits the simultaneous light-off of both fuels

(g) Requires flame detector(s) in accordance with 5.4.4 to supervise any of the following

conditions:

(5.7.2(3)(g)1.) Igniter flame as permitted by igniter class

(5.7.2(3)(g)2.) Gas firing

(5.7.2(3)(g)3.) Oil firing

(5.7.2(3)(g)4.) Combined gas and oil firing

(h) Burner flame detectors permitted to supervise multiple the fuels used


This subsection shall define the requirements and procedures for an automated light-off and



Commented [TJ18]: Delete “Automated” so that 5.7.3 applies to either manual or automatic conditions. Doing so is the basis for deleting 5.7.4.


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5.7.3.2





(4) The capability to signal the combustion control system to bias up the airflow, to position the

control valve for the second fuel to light-off, and to open the safety shutoff valve(s) of the fuel being

introduced

(5) The capability to bias up the airflow by a preset value in response to a fuel transfer signal while

the airflow remains in automatic mode



in the listed order:










(9)*) Establish ignition energy in accordance with manufacturer's instructions. Where an igniter is






fuel.


A.5.7.3.3 (9)

Ignition energy may be provided by the fuel being fired for the subsequent fuel light-off.

Commented [TJ19]: Suggest addition of Annex to clarify that the use of an Igniter is not always required.

Formatted: Font: Not Bold


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When gas is introduced as the second fuel, the light-off cycle for the gas shall accomplish the

following in the listed order:







fuel input of fuel gas in light-off.




to the burner.




fuel.



This subsection shall define the requirements and procedures required for the manual light-off and




5.7.4.2

The combustion control system shall have the capability to manually bias up the airflow while the

airflow remains in automatic mode.

5.7.4.2.1




in the order listed:



Formatted: Space Before: 6 pt


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(11) Place the combustion control system into the required mode for controlling the input rate of

each fuel.









(5) Establish ignition energy in accordance with manufacturer’s instructions. Where an igniter is



to the burner.




fuel.







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(4) Purge oil passages of the oil atomizer, where usedif required.










5.7.5.3.1

Any of the following operating conditions shall accomplish a safety shutdown of the oil supply to the

burner (i.e., fuel trip):


(2) Low temperature of heated oils, where used

(3) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches, one


safety shutdown on low pressure

(4) High temperature of heated oil, where used

5.7.5.3.2



5.7.5.4.1

Either of the following conditions shall accomplish a safety shutdown of the gas supply to the burner

(i.e., fuel trip):



5.7.5.4.2


Formatted: Space Before: 0 pt


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(4) Power failure





5.8.1* General.

The equipment and procedures of 5.8.1.1 through 5.8.1.4 shall be used to avoid a hazardous

furnace condition when operation of the boiler is transferred from fuel oil to fuel gas or from fuel gas

to fuel oil without requiring a shutdown of the boiler.


When the combustion control system and the burner management system are both designed for fuel

transfer and simultaneous firing of oil and gas fuels on a continuous basis, the requirements of

Section 5.7 shall apply.

5.8.1.2



5.8.1.3




5.8.1.4







(a) Proportioning fuel flow for each fuel individually

(b) Limiting total fuel input to the maximum capacity of the boiler

Commented [TJ20]: Propose to delete. Not sure what it means?

Commented [TJ21]: Propose to delete. Not sure what it means?

Commented [TJ22]: Propose to delete. We removed this requirement in 5.7.3.3 (9) and A.5.7.3.3 (9)

Commented [TJ23]: Propose to delete, exact requirement in 5.7.1.2

Commented [TJ24]: Propose to delete, exact requirement in 5.7.1.3


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(c) Controlling a minimum airflow rate

(d) Controlling minimum input rates of each fuel

(e) Providing a stable return to design air-fuel ratio after the trip or shutdown of either fuel


(a) A gas-firing mode in which oil cannot be fired

(b) An oil-firing mode in which gas cannot be fired

(c) A gas-oil-firing mode that permits simultaneous firing of both fuels, provided all interlocks

for both fuels are satisfied, including light-off position for both fuel valves

(d) A control device, transfer timer, and an alarm for 5.8.2(3) (c), to limit continuous operation

in this mode



(b) Provides anProvidesan independent interlock to each fuel being fired that automatically

shuts down the affected fuel with operation continuing on the unaffected fuel in a stable

manner; shutdown of both fuels is permitted

(c) Provides that both the first and second fuels be introduced with their flow control valves in

light-off positions

(d) Provides an interlock action that will trip either fuel should its respective flow control valve

leave deviate from a predetermined setting during fuel transfer

(e) Provides for the introduction of the second fuel without requiring a boiler purge

(f) Requires a manual reset following any interlock shutdown

(g) Prohibits the simultaneous light-off of both fuels

(h) Provides detector(s) to supervise any of the following conditions:

(5.8.2(4)(h)1.) Igniter flame as permitted by igniter class

(5.8.2(4)(h)2.) Gas firing

(5.8.2(4)(h)3.) Oil firing

(5.8.2(4)(h)4.) Combined gas and oil firing

(i) Burner flame detectors shall be permitted to supervise multiple fuels.

5.8.3 Simultaneous Firing of Oil and Gas for Fuel Transfer Only (Automated Transfer).).

This subsection shall define the requirements and procedures to be used for an automated transfer

of operation from one fuel to a second fuel without requiring a shutdown of the burner.



Commented [TJ25]: Propose to delete “Automatic Transfer” and use one set of requirements for any fuel transfer.


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5.8.3.1.1

The combustion control system shall have the capability to automatically increase the airflow by a

preset value in response to a fuel transfer signal.

5.8.3.1.2


5.8.3.1.3

The fuel transfer mode shall have the capability to signal the combustion control system to increase

airflow and open the safety shutoff valve(s) of the fuel being introduced.


When oil is introduced as the second fuel, the transfer cycle from gas to oil shall be in the following

order:


















When gas is introduced as the second fuel, the transfer cycle from oil to gas shall be in the following

order:




Commented [TJ26]: Add same Annex text as in A.5.7.3.3 (9)


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to the burner.










This subsection shall define the requirements and procedures to be used for a manual transfer of

operation from one fuel to a second fuel without requiring a shutdown of the burner.



5.8.4.1.1


5.8.4.1.2

Manual shutoff valves shall be provided at the burner, downstream of the safety shutoff valves for

each fuel.

5.8.4.1.3



When oil is introduced as the second fuel, the procedure to transfer from gas to oil shall be as

follows:


manufacturer's instructions as required.


Commented [TJ27]: Add same Annex text as in A.5.7.3.3 (9)


of 249









(a) When the oil safety interlocks are satisfied, the oil safety shutoff valves open.


(10) Slowly close the manual gas shutoff valve while observing the gas pressure downstream of

the valve until the gas pressure starts to drop. At this point, the gas flow rate is controlled by the

manual valve instead of by the control valve.

(11) Slowly close the manual gas valve while simultaneously opening the manual oil valve to light

the oil flame from the gas flame and proceed as follows:

(a) Continue to increase the oil-firing rate while cutting back on the gas-firing rate to maintain

a constant heat input of the combined fuels to the burner, until the manual gas valve is closed

and the manual oil valve is fully open.




valves operated.





When gas is introduced as the second fuel, the procedure to transfer from oil to gas shall be as

follows:









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(a) When the gas safety interlocks are satisfied, the gas safety shutoff valves open.


(8) Slowly close the manual oil valve while observing the oil pressure downstream of the valve

until the oil pressure starts to drop. At this point, the oil flow is controlled by the manual valve

instead of by the control valve.

(9) Slowly close the manual oil valve while simultaneously opening the manual gas valve to light

the gas flame from the oil flame, then proceed as follows:

(a) Continue to increase the gas-firing rate while cutting back on the oil-firing rate to maintain

a constant heat input of the combined fuels to the burner until the manual oil valve is closed

and the manual gas valve is fully open.




valves operated.








Safety shutdowns shall be initiated in accordance with 5.7.5.3 through 5.7.5.5 .


5.9.1* General.

Where a burner is equipped with main and auxiliary oil atomizers for the purpose of changing

atomizers for maintenance without affecting the boiler load, the changeover of atomizers shall be

carried out manually under stable firing conditions by a trained operator.

5.9.1.1



5.9.1.2




Commented [TJ28]: Propose to delete all in the Manual Transfer section.

Commented [TJ29]: Do we wish to add same Annex text as in A.5.7.3.3 (9) here?


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5.9.1.3






(2) A combustion control system that is capable of limiting the total fuel input to the maximum

capacity of the boiler and that has the capability to manually adjust the airflow

(3) A safety interlock system in accordance with 5.4.6 that also prohibits the simultaneous light-off

of both atomizers

(4) Manual oil shutoff valves at the burner, downstream of the safety shutoff valves for each

atomizer


(6) Manual atomizing media shutoff valves for each atomizer except on mechanically atomized

systems


The procedures for a manual transfer of operation from one oil atomizer (main or auxiliary) to a

second oil atomizer (auxiliary or main) without requiring a shutdown of the burner shall be as

follows:






(5) Slowly close the manual shutoff valve while observing the oil pressure downstream of the

valve until the oil pressure starts to drop. At this point, the oil flow rate is controlled by the manual

valve instead of by the control valve.

(6) For non mechanicallynonmechanically atomized oil atomizers, slowly open the second

atomizing medium shutoff valve until it is fully open.

(7) Slowly close the manual oil valve for the atomizer in service while simultaneously opening the

manual oil valve of the second atomizer to light the second atomizer from the first and proceed as

follows:

(a) Continue to slowly increase the oil-firing rate on the second atomizer while cutting back

on the firing rate of the first atomizer to maintain a constant heat input of the combined

atomizers until the manual valve of the first atomizer is closed and the manual oil valve of the

second atomizer is fully open.

Commented [TJ30]: Do we wish to add same Annex text as in A.5.7.3.3 (9)


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(b) Excess air shall be maintained at all times by continuous observation of the burner flame

or by observation of the air-fuel ratio, oxygen indicator, or opacity indicator, if provided.


valves operated.





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The light-off cycle

for a burner with a Class 3 igniter shall accomplish the following in the listed order:

(1)




(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils,shut off igniter.






(1)




(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils,prove the main flame (see 5.4.4.1.1.2 ) and proceed as follows:






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5. shall be in accordance with Table 5. 6.2.6.2. 3 Class 1 Igniter.


(1)




(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils,prove the main flame (see 5.4.4.1.1.1 ) and proceed as follows:





NFPA_85_Proposal_Igniters.pdf


This proposal intents to replace the text containing requirements for igniters with a table. The table does not intend to change the requirements but to make them more easily understood, especially the differences between the 3 types of igniters.


Submitter Full Name: Theodore Lemoff

Organization: TLemoff Engineering

Street Address:

City:

State:

Zip:

Submittal Date: Wed Dec 14 00:36:19 EST 2016



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Item 21.8: Light off cycle steps for Class 3, Class 2, and Class 1 igniters.

Use only the column for the Class of igniter used

Light off cycle steps Class 3 Igniter Class 2 Igniter Class 1 Igniter

Verify that the light-off cycle for a burner accomplishes the following in the listed order:

Required

Required

Required

1) Energize the ignition transformer and igniter fuel valves.

Required

Required

Required

2) Prove igniter flame within 10 seconds of the energization of the igniter fuel valves and proceed as follows

Required

Required

Required


Required

Required

Required


Required

Required

Required

3) After a maximum of 10 seconds for gas and Nos. 2 and 4 oil or15 seconds for Nos. 5 and 6 oil →

Shut off the igniter

Prove the main flame and proceed as follows:

(a) If proven, release to combustion control for modulation, where provided. (b) If not proven, establish safety shutdown.

4) Prove main flame (see 5.4.4.1.1.3 and 5.4.4.1.1.4) and proceed as follows:

Required

Not Applicable Not Applicable


Required



Required


* Class 3 special igniters do not require proof of igniter operation **See 5.4.1.1.2


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Public Input No. 219-NFPA 85-2017 [ Section No. 5.6.2.6.2.1 ]



(1)



(4) If not proven,

establish safety shutdown

(a) initiate a master fuel trip .

(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils, shutoff igniter.

(6) Prove main flame (see 5.4.4.1.1.3 and 5.4.4.1.1.4) and proceed as follows:


(8) If not proven,




Replacing the text "establish a safety shutdown" with "initiate a master fuel trip".




Street Address:

City:

State:

Zip:




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(1)



(4) If not proven,





(7) If not proven,








Street Address:

City:

State:

Zip:




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(1)



(4) If not proven,





(7) If not proven,








Street Address:

City:

State:

Zip:




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5.6.2.6.4.3* Safety Shutdown Master Fuel Trip .

Any of the conditions in 5.6.2.6.4.3(A) or 5.6.2.6.4.3(B) shall accomplish a safety shutdown initiate amaster fuel trip , and the burner shall not be allowed to recycle until a trained operator determines thecause of the shutdown and takes the necessary corrective action to ensure that conditions are withinspecified operating limits prior to restarting.

(A)







(6) Power failure


(8) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches (one locatedat the service connection and the other at the burner, either one of which shall initiate a safetyshutdown master fuel trip on low pressure)



(B)







(6) Power failure








Street Address:

City:

State:


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Zip:



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The safety shutdown cycle shall accomplish the following in the listed order and shall activate an alarm:









(9) Require manual reset, which may be down either at the device or in the BMS .


Clarifies that manual reset device are acceptable, but not mandatory if reset can be done at the BMS.




Street Address:

City:

State:

Zip:

Submittal Date: Mon Dec 19 11:31:52 EST 2016


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5.6.2.6.4.4 Safety Shutdown Master Fuel Trip Cycle.

The safety shutdown master fuel trip cycle shall accomplish the following in the listed order and shallactivate an alarm:











Replacing the text "safety shutdown" with "master fuel trip".




Street Address:

City:

State:

Zip:



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(1)

(2) Prove the igniter flame within 10 seconds of the energization of the igniter fuel valves and proceed asfollows (for a Class 3 special igniter, proof of igniter operation is not required):

(3) If proven, admit fuel to main burner.

(4) If not proven,



(5) After a maximum of 10 seconds for gas and Nos. 2 and 4 oils or 15 seconds for Nos. 5 and 6 oils, shutoff the igniter.



(8) If not proven,








Street Address:

City:

State:

Zip:




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(11) A safety interlock system burner management system with the following capabilities:









(20) Gas firing

(21) Oil firing





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Note to editor: The only change is to paragraph 5.7.2 is to sub-part (3). While other underlining is shown, the other text was not affected by this change.

This change revises sub-part (3) to replace "safety interlock system" with "burner management system". "Burner management system" is a defined term, and it appears to the appropriate term to use in this sentence.



Public Input No. 153-NFPA 85-2016 [Section No.5.4.6]

Using the defined term "Burner ManagementSystem".






Street Address:

City:

State:

Zip:



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(11) A safety interlock system Interlocks and associated devices with the following capabilities:









(20) Gas firing

(21) Oil firing





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Street Address:

City:

State:

Zip:



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5.7.5.3* Oil Safety Shutdowns Fuel Trip .

5.7.5.3.1

Any of the following operating conditions shall accomplish a safety shutdown trip of the oil supply to theburner (i.e., fuel trip):



(3) Loss of atomizing medium, where used, as interlocked by flow or two pressure switches, one locatedat the service connection and the other at the burner, either one of which shall initiate a safetyshutdown on low pressure


5.7.5.3.2

A complete boiler safety shutdown master fuel trip shall occur if oil is the only fuel being fired.


Replacing the text "safety shutdown" with "fuel trip".




Street Address:

City:

State:

Zip:



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5.7.5.4 Gas Safety Shutdowns Fuel Trip .

5.7.5.4.1

Either of the following conditions shall accomplish a safety shutdown trip of the gas supply to the burner(i.e., fuel trip):



5.7.5.4.2

A complete boiler safety shutdown master fuel trip shall occur if gas is the only fuel being fired.


Replacing the text "safety shutdown" with "trip".




Street Address:

City:

State:

Zip:



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5.7.5.5 Boiler Safety Shutdowns Master Fuel Trip .

Any of the following conditions shall accomplish a complete safety shutdown initial a master fuel trip of theboiler:




(4) Power failure





Replacing the text "accomplish a complete safety shutdown" with "initiate a master fuel trip".




Street Address:

City:

State:

Zip:



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(13) A safety interlock burner management system with the following capabilities:










(23) Gas firing

(24) Oil firing




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Note to editor: The only change is to paragraph 5.8.2 is to sub-part (4). While other underlining is shown, the other text was not affected by this change.












Street Address:

City:

State:

Zip:



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(13) A safety interlock system Interlocks and associated devices with the following capabilities:










(23) Gas firing

(24) Oil firing




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Street Address:

City:

State:

Zip:



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Public Input No. 222-NFPA 85-2017 [ Sections 5.8.4.2, 5.8.4.3 ]

Sections 5.8.4.2, 5.8.4.3


When oil is introduced as the second fuel, the procedure to transfer from gas to oil shall be as follows:

(1) Where a Class 1 or Class 2 igniter is available, place it in service in accordance with themanufacturer's instructions as required.









(10) When the oil

safety

(a) interlocks are satisfied, the oil safety shutoff valves open.


(11) Slowly close the manual gas shutoff valve while observing the gas pressure downstream of the valveuntil the gas pressure starts to drop. At this point, the gas flow rate is controlled by the manual valveinstead of by the control valve.

(12) Slowly close the manual gas valve while simultaneously opening the manual oil valve to light the oilflame from the gas flame and proceed as follows:

(13) Continue to increase the oil-firing rate while cutting back on the gas-firing rate to maintain aconstant heat input of the combined fuels to the burner, until the manual gas valve is closed andthe manual oil valve is fully open.







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When gas is introduced as the second fuel, the procedure to transfer from oil to gas shall be as follows:








(8) When the gas

safety

(a) interlocks are satisfied, the gas safety shutoff valves open.


(9) Slowly close the manual oil valve while observing the oil pressure downstream of the valve until the oilpressure starts to drop. At this point, the oil flow is controlled by the manual valve instead of by thecontrol valve.

(10) Slowly close the manual oil valve while simultaneously opening the manual gas valve to light the gasflame from the oil flame, then proceed as follows:

(11) Continue to increase the gas-firing rate while cutting back on the oil-firing rate to maintain aconstant heat input of the combined fuels to the burner until the manual oil valve is closed and themanual gas valve is fully open.














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5.8.5 Safety Shutdowns Fuel Trips .

Safety shutdowns Fuel trips shall be initiated in accordance with 5.7.5.3 through 5.7.5.5.


Replacing the text "Safety Shutdown" with "Fuel Trips".




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(3) A safety interlock burner management system in accordance with 5.4.6 that also prohibits thesimultaneous light-off of both atomizers

















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(3) A safety interlock system Interlocks in accordance with 5.4.6 that also prohibits the simultaneouslight-off of both atomizers









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Public Input No. 148-NFPA 85-2016 [ Section No. A.5.4.2.3 ]

A.5.4.2.3

Main burner gas supply. Special precautions are required in locating the vent pipe from the automatic bleedvalve so that heavier-than-air, vented gases do not accumulate in depressions or in confined areas. Analternative to the automatic venting of heavier-than-air gases is to eliminate the main vent valve frombetween the two main safety shutoff valves use a valve proving system . See Figure A.5.4.2.3 for a typicalmain gas burner system arrangement.

Figure A.5.4.2.3 Typical Fuel Supply Systems and Safety Controls for Gas Burner.


valve proving systems do not introduce any new hazards when used with LP gases.




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Public Input No. 3-NFPA 85-2016 [ Section No. A.5.4.2.3 ]

A.5.4.2.3

Main burner gas supply. Special precautions are required in locating the vent pipe from the automaticbleed valve so that heavier-than-air, vented gases do not accumulate in depressions or in confined areas.An alternative to the automatic venting of heavier-than-air gases is to eliminate the main vent valve frombetween the two main safety shutoff valves. See Figure A.5.4.2.3 for a typical main gas burner systemarrangement.

Figure A.5.4.2.3 Typical Fuel Supply Systems and Safety Controls for Gas Burner.



G85-30_edited.jpg

Edited Figure A.5.4.2.3 Typical Fuel Supply Systems and Safety Controls for Gas Burner. Shows alternate arrangement of the vent line manual shutoff valve for leakage testing (K) being placed downstream of the automatic vent valve (C) with an additional leakage test connection (L) between the two valves. With this alternate piping connection, a leak test of the vent valve (C) can be performed while the boiler is in operation (Vent valve (C) energized) by closing the vent line manual shutoff valve (K) and performing a bubble test at the leakage test connection (L).


Figure A.5.4.2.3 Typical Fuel Supply Systems and Safety Controls for Gas Burner. With the current arrangement of the vent valve downstream of the manual shutoff valve in the vent line, there is no way to test the vent valve for leakage. The uploaded diagram shows an alternate arrangement of the vent line manual shutoff valve for leakage testing (K) being placed downstream of the automatic vent valve (C) with an additional leakage test connection (L) between the two valves. With this alternate piping connection, a leak test of the vent valve (C) can be performed while the boiler is in operation (Vent valve (C) energized and closed) by closing the vent line manual shutoff valve (K) and performing a bubble test at the new leakage test connection (L).


Submitter Full Name: Mike Elkevizth

Organization: Data Control Systems

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Public Input No. 140-NFPA 85-2016 [ Section No. A.5.4.4.1.3 ]

A.5.4.4.1.3

For heavier-than-air gases and gas-fired igniters, many oil-fired boilers are equipped with propane or otherliquefied petroleum gas (LP-Gas)–fired igniters. Special precautions are required in locating the vent pipefrom the automatic bleed valve so that heavier-than-air, vented gases do not accumulate in depressions orin confined areas. An A VPS is a more desirable alternative to the automatic venting of heavier-than-airgases is to eliminate the igniter vent valve from between the two igniter safety shutoff valves. (See FigureA.5.4.4.1.)


There is a device of equivalent safety that does not introduce other hazards when used with LP type gases, and that is the VPS. The Annex should recommend the VPS in this case rather than removing a safety device,




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Public Input No. 115-NFPA 85-2016 [ Section No. A.5.4.4.6.3 ]

A.5.4.4.6.3

Analyzers could contain heated elements that exceed the autoignition temperature of many fuels. Zirconiumoxide analyzers, commonly used for oxygen analysis, contain an element heated to 704°C (1300°F). Thishigh temperature element presents a potential ignition source to unburned fuel that could be present duringpre-purge or at startup. Some analyzers are designed to protect the sampled space from the ignition sourceby providing flashback protection (such as flame arresters in the sample gas path). It should be noted,however, that flame arrestors might only work below a certain temperature which is usually notquantified, might not quench a flame as well once it becomes corroded, and might induce a speed ofresponse delay that could be detrimental to the control or protection strategy. Consideration should begiven to powering down analyzers during boiler or fuel trip situations if they can exceed the autoignitiontemperature of the fuel being fired. Alternatively, consideration could be given to utilizing analyzer technologiesthat operate below autoignition temperatures or utilizing installation techniques that mount the analyzer external to theprocess where the flue gas sampling can be shutoff during a boiler or fuel trip situation.


None of the insurers contacted had any specific loss history that they could identify on oxygen analyzer initiated fires so it is difficult to determine how much of a hazard this situation actually provides. There is not, therefore, justification to state a mandatory requirement beyond the present requirements found in 5.4.4.6.3, 6.4.1.2.4.6(2) and 7.6.2.1.1(10) in NFPA 85-2015. Additional Annex material, however, would be helpful so that was developed based on information provided by a number of analyzer manufacturers.



Public Input No. 116-NFPA 85-2016 [Section No. A.6.4.1.2.4.6(2)]

Public Input No. 117-NFPA 85-2016 [Section No. A.7.6.2.1.1(10)]


Submitter Full Name: Dale Evely

Organization: Southern Company Services Inc

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Submittal Date: Thu Nov 17 13:04:58 EST 2016


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Attachment D: Review of Fundamentals Technical Committee actions


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First Revision No. 102-NFPA 85-2017 [ Section No. 1.1.2 ]

1.1.2

This code covers strength of the structure, operation and maintenance procedures, combustion and draftcontrol equipment, safety interlocks, alarms, trips, and other related controls that are essential to safeequipment operation.


Submitter Full Name: Laura Montville

Organization: [ Not Specified ]

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Committee Statement

Committee Statement: To align with the interlock definitions included in Chapter 3. (FRs 103, 104, 105)

Response Message:


National Fire Protection Association Report http://localhost:8084/TerraViewWeb/ContentFetcher?commentParams=...

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Committee Input No. 135-NFPA 85-2017 [ Section No. 1.1.4 ]

1.1.4

Chapter 5, Single Burner Boilers, covers single burner boilers that fire the following fuels:

(1) Fuel Natural gas as defined in 3.3. 64 71 .10.

(2)

(3) Fuel oil as defined in 3.3.63.3

Fuel gas and fuel

(4) of Grades 2, 4, 5, or 6

(5) Gas and oil that are fired simultaneously for fuel transfer

(6) Fuel gas Gas and fuel oil that are fired simultaneously and continuously

(7) Non-commercial grade fuel gases




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Committee Statement

CommitteeStatement:

The scope of Chapter 5 written in Chapter 1 needs to match the contents of the equipment specificchapter. The Fundamentals Committee will reconsider a revision to the Chapter 5 scope at theSecond Draft meeting, once additional language has been added to Chapter 5 by the SBBCommittee to cover the other fuels.

----

The SBB Committee wishes to amend the scope statement to define and address the use ofnon-commercial fuels in its chapter. Non-commercial fuels such as landfill gas, process off-gases,etc. are used in increasing single burner applications. The Technical Committee will continue to addmaterial to address specific concerns and requirements when using these types of fuels.

ResponseMessage:


* Other commercial grade fuel gas having a calorific value and characteristics similar to natural gas


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First Revision No. 108-NFPA 85-2017 [ Section No. 1.1.9.1 ]

1.1.9.1

Where solid fuel is fired simultaneously with other fuels (e.g., a solid fuel stoker fired in combination withfuel gas, fuel oil, or pulverized auxiliary fuel), additional controls and interlocks shall include those coveredin Chapters 5, 6, and 9.

Exception No. 1: The purge requirements of Chapters 5 and 6 shall not be required when the stoker isfiring and the boiler is on-line. In those cases, if no cooling air is being provided to the auxiliary burners, apurge of their associated air supply ducts shall be provided.

Exception No. 2: Where fuel oil or fuel gas is fired in a supervised manual system in accordance withChapter 5 , the excessive steam pressure interlock shall not be required.




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Committee Statement

CommitteeStatement:

The FUN Technical Committee decided that the STO and SBB Technical Committees shouldaddress these exceptions in their respective chapters.

ResponseMessage:

Public Input No. 23-NFPA 85-2016 [Section No. 1.1.9.1]


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Committee Input No. 101-NFPA 85-2017 [ Chapter 2 ]

Chapter 2 Referenced Publications

2.1 General.

The documents or portions thereof listed in this chapter are referenced within this code and shall beconsidered part of the requirements of this document.

2.2 NFPA Publications.

National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169-7471.

NFPA 30, Flammable and Combustible Liquids Code, 2015 edition.

NFPA 31, Standard for the Installation of Oil-Burning Equipment, 2011 edition.

NFPA 54, National Fuel Gas Code, 2015 edition.

NFPA 56 Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable GasPiping Systems,2014 edition.

NFPA 68 Standard on Explosion Protection by Deflagration Venting,2013 edition.

NFPA 69, Standard on Explosion Prevention Systems, 2014 edition.

NFPA 70® , National Electrical Code®, 2014 edition.

2.3 Other Publications.

2.3.1 ASCE Publications.

American Society of Civil Engineers, 1801 Alexander Bell Drive, Reston, VA 20191-4400.

ASCE 7, Minimum Design Loads for Buildings and Other Structures, 2010.

2.3.2 ASME Publications.

American Society of Mechanical Engineers, Two Park Avenue, New York, NY 10016-5990.

ASME B31.1, Power Piping, 2012 2016 .

ASME B31.3, Process Piping, 2012 2016 .

2.3.3 ASTM Publications.

ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.

ASTM D388, Standard Classification of Coals by Rank, 2012 2015 .

ASTM D396, Standard Specification for Fuel Oils, 2012 2016 .

ASTM D409/D409M , Standard Test Method for Grindability of Coal by the Hardgrove-Machine Method,2012 2016 .

ASTM D1655, Standard Specification for Aviation Turbine Fuels, 2012 2016c .

ASTM D2880, Standard Specification for Gas Turbine Fuel Oils, 2003, reaffirmed 2010 2015 .

2.3.4 CGA Publications.

Compressed Gas Association, 14501 George Carter Way, Suite 103, Chantilly, VA 20151-2923 1788 .

ANSI/ CGA G-2.1/ANSI K61.1 , Safety Requirements for the Storage and Handling of AnhydrousAmmonia, 1999 2014

2.3.5 FCI Publications.

Fluid Controls Institute, 1300 Sumner Avenue, Cleveland, OH 44115.

ANSI/FCI 70-2, Control Valve Seat Leakage, 2006 2013 .


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2.3.6 Government Publications.

U.S. Government Printing Publishing Office, 732 North Capitol Street NW, Washington, DC20402 20401-0001 .

Title 29, Code of Federal Regulations, Part 1926.32, “General Safety and Health Provisions.”

2.3.7 IEC Publications.

International Electrotechnical Commission, 3, rue de Varembé, P.O. Box 131, CH-1211, Geneva 20,Switzerland.

IEC 61508, Functional Safety of Electrical/Electronic Programmable Electronic Safety-Related Systems,2010.

2.3.8 Military Specifications.

Department of Defense Single Stock Point, Document Automation and Production Service, Building 4/D,700 Robbins Avenue, Philadelphia, PA 19111-5094.

MIL-T-5624, Turbine Fuel, Aviation, Grade JP4, JP5, and JP5/JP8 ST, 1995.

2.3.9 Other Publications.

Merriam-Webster’s Collegiate Dictionary, 11th edition, Merriam-Webster, Inc., Springfield, MA, 2003.

2.4 References for Extracts in Mandatory Sections.

NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings andManufactured Homes,2013 2016 edition.

NFPA 40, Standard for the Storage and Handling of Cellulose Nitrate Film,2011 2016 edition.

NFPA 72® , National Fire Alarm and Signaling Code,2013 2016 edition.

NFPA 850, Recommended Practice for Fire Protection for Electric Generating Plants and High VoltageDirect Current Converter Stations, 2015 edition.




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Committee Statement

CommitteeStatement:

The committee will review the referenced documents at the second draft meeting so that theywill have a more timely picture of what has been updated since the last edition was issued.



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3.3.25.3 Manual Supervised Burner Management System.

A burner management system by which a furnace is purged and a burner is started, ignited, and stoppedmanually . Interlocks are included to ensure that the operation follows established, proper procedures. withsupervision by interlocks.




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Committee Statement

Committee Statement: To align with the definition of interlock revised by FR 103.

Response Message:



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First Revision No. 139-NFPA 85-2017 [ Section No. 3.3.63.2.1 ]

3.3.63.2.1 Pulverized Coal.

Coal that is reduced to fine particles.

A.3.63.2.1 Pulverized Coal is typically reduced to a size such that at least 50 percent can pass through a200-mesh (74 microns) sieve.




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Committee Statement: The definition is revised to remove requirements per the Manual of Style.

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3.3.63.6 3.1* Liquefied Petroleum Gas ( LP-Gas) .

A material that

Any material having a vapor pressure not exceeding that allowed for commercial propane that iscomposed predominantly of

any of

the following hydrocarbons , either by themselves (except propylene) or as mixtures

thereof

: propane, propylene,

n-butane, isobutane

butane (normal butane or isobutane) , and butylenes. [58 2017]

A.3.3.63.3.1 Liquefied Petroleum Gas (LP-Gas). In the pure state

propylene (Chemical Abstract Service 105-07- 01) has a vapor

pressure of 132.8 psig (915.72 kPa) at 70°F (21.1°C). The vapor

pressure of commercial propane (Chemical Abstract Service

74-98-6) at 70°F (21.1°C) is 124 psig (855 kPa). Although

commercial propane can contain some propylene, as in impurity,

propylene in the pure state does not meet the definition of

LP-Gas. Propylene in the pure state is commonly found in use

as an industrial fuel gas. (See NFPA 51.) [58 2017]




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Committee Statement

CommitteeStatement:

The definition is updated to be consistent with the applicable NFPA code, and the definition isrelocated to be a subdefinition of Fuel Gas.

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3.3.63.9 3.2* Natural Gas.

A gaseous fuel occurring in nature and consisting mostly of a mixture of organic compounds, normallymethane, material that is composed primarily of methane and that can contain minor quantities of ethane,propane, nitrogen, and butane. other components.

A.3.3.63.3.2

The calorific value of natural gases varies between about 700 Btu/ft 3 and 1500 Btu/ft 3 ( 26.1 MJ/m3 and

55.9 MJ/m3 (700 Btu/ft 3 and 1500 Btu/ft 3 ), the majority averaging 1000 Btu/ft 3 ( 37.3 MJ/m3

(1000 Btu/ft 3 ).




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Committee Statement

CommitteeStatement:

The definition is updated to be consistent with NFPA 59A Liquefied Natural Gas, with someappropriate modification, and moved to be a subdefinition of Fuel Gas.

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3.3.63.10 * Pulverized Fuel.

Solid fuel that is reduced to fine particles.

A.3.3.63.10 Pulverized fuel is typically reduced to a size such that at least 50 percent will pass through a200-mesh (74 microns) sieve.




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Committee Statement: The definition is revised to remove requirements per the Manual of Style.

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3.3.64 63.3 Fuel Gas (Gas Fuel).

Gaseous fuels defined as Natural Gas (see 3.3.63.9) or LP-Gas (see 3.3.63.6).




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Committee Statement: Fuel gas belongs as a subdefinition of Fuel.

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3.3.66 Fuel Trip.

The automatic The total shutoff of a specific fuel as the result of an interlock or operator action .




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CommitteeStatement:

This revision is based on the revised and new definitions for trip and interlock. Note that theoperator action is considered an interlock.

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3.3.70 Hardwired.

The method of interconnecting signals or interlocks or devices to a logic system or between logic systemsusing a dedicated interconnection for each individual signal. When the term hardwired is applied to the logicsystem itself, it refers to the method of using individual devices and interconnecting wiring to program andperform the logic functions without the use of software-based logic solvers.




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Committee Statement

CommitteeStatement:

This revision is based on the revised definition of interlocks. Interlocks will now be defined as"functions" rather than "devices."

ResponseMessage:



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First Revision No. 141-NFPA 85-2017 [ Sections 3.3.73.1, 3.3.73.2, 3.3.73.3 ]

Sections 3.3.73.1, 3.3.73.2, 3.3.73.3

3.3.73.1 * Class 1 Igniter.

An igniter that is applied to ignite the fuel input through the burner and to support ignition under any burnerlight-off or operating conditions. Its location and capacity are such that it will provide sufficient ignitionenergy , generally in excess of 10 percent of full load burner input, at its associated burner to raise anycredible combination of burner inputs of both fuel and air above the minimum ignition temperature.


An igniter that is applied to ignite the fuel input through the burner under prescribed light-off conditions. It isalso used to support ignition under low load or certain adverse operating conditions. The range of capacityof such igniters is generally 4 percent to 10 percent of full load burner fuel input.


A small igniter applied particularly to fuel gas and fuel oil burners to ignite the fuel input to the burner underprescribed light-off conditions. The capacity of such igniters generally does not exceed 4 percent of the fullload burner fuel

A.3.3.73.1 The heat input of a Class 1 Igniter is generally in excess of 10 percent of maximum burner heatinput.

A.3.3.73.2 The heat input of a Class 2 Igniter is generally 4 percent to 10 percent of maximum burner heatinput.

A.3.3.73.3 The heat input of a Class 3 Igniter generally does not exceed 4 percent of maximum burnerheat input.

Supplemental Information

File Name Description

FR_141_A.3.3.63.1-3.docx




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Committee Statement

CommitteeStatement:

This revision removes the supplemental information from the igniter class definition, leaving theintended functional requirements intact, and relocates the supplemental information to theAnnex.

ResponseMessage:

Public Input No. 211-NFPA 85-2017 [New Section after A.3.3.33]


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Public Input No. 201-NFPA 85-2017 [Sections 3.3.73.1, 3.3.73.2, 3.3.73.3]


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Committee Input No. 143-NFPA 85-2017 [ New Section after 3.3.73.2 ]

3.3.73.3* Class 2 Special Igniter: An integrated burner-igniter system that utilizes a staged ignition systemwithin the burner. The primary igniter shall utilize oil or natural gas, or a plasma arc to ignite a portion of themain fuel stream which then provides ignition to the remainder of hte fuel stream. It is also used to supportignition under low load conditions where the main flame is proven.




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Committee Statement

CommitteeStatement:

The addition of these definitions relating to plasma arc igniters is contingent on action by the MBBCommittee.

---

Problem statement: Existing igniter systems are typically independent of the burner they areintended to ignite. A new technology is available whereby a portion of the main fuel stream is ignitedinternally in the burner barrel using oil, gas or plasma. The technology necessitates adjustments inoperating methodology for proper function. A task group comprised of members from BCS-MBB hasstudied this technology. This paragraph, in conjunction with other proposed paragraphs, addressesthat new technology.

SUBSTANTIATION: The proposed code revisions will provide minimum safety requirements that canenable US coal fired power plants to respond to real time market conditions in a timely manner. Thetechnology is desirable as it reduces or eliminates the amount of premium fuel used to start a boiler.

The technology has been successfully applied outside the US with installations in over 1,000 coalfired boilers in both the plasma and oil igniter form, and is available from multiplesuppliers/manufacturers. These installations have helped determine the suitability of the technologyand gives confidence in its safety potential. To enhance user safety a new igniter classification (a"Special" derivative of the existing Class II) which requires usage under prescribed conditions only.

The key distinguishing characteristic between the igniter classes in NFPA 85 is the difference inigniter ability to tolerate process variations. Based on the igniter ability to function under difficultconditions, the implementation and the privileges of the igniter class vary, Class I can be used under'all credible' conditions (3.3.73.1) but Class II can be used under 'prescribed' conditions only(3.3.73.2)

The restrictions to prescribed conditions is also required due to the difficullty in igniter flame provingin some of these applications for the plasma arc style. The location of the igniter fllame inside theburner barrel, where it cannot be reliably sensed, requires the use of a proven main flame under'non-initial' start-up conditions for safe operation.

This revision will help avoid unsafe application of this new technology by providing clear and


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consistent minimum safety requirements.

ResponseMessage:

Public Input No. 157-NFPA 85-2016 [New Section after 3.3.73.2]



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* Integrated Burner-Igniter System

An igniter integral to a staged ignition burner assembly, whereby a portion of the main fuel streamis raised to a temperature above its auto-ignition temperatureand this heated fuel then ignites theremainder of the main fuel stream as it enters the furnace.




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Committee Statement

CommitteeStatement:


---

Problem Statement

Existing igniter systems are typically independent of the burner they are intended to ignite. A newtechnology is available whereby a portion of the main fuel stream is ignited internally in the burnerbarrel using oil, gas or plasma. The technology necessitates adjustments in operations methodologyfor proper function. A task group comprised of members from BCS-MBB has studied this technology.This paragraph, in conjunction with other proposed paragraphs, addresses that new technology.

Substantiation

The proposed code revision will provide minimum safety requirements of a new technology that canenable US coal fired power plants to respond to real time market conditions in a timely manner. Thetechnology is desirable because it reduces, or eliminates, the amount of premium support fuel usedto warm up a boiler and to bring on successive mill groups.

The technology has been successfully applied outside the US with installations in over 1,000 coalfired boilers in both the plasma and oil igniter form; and is available from multiplesuppliers/manufacturers. These installations have helped determine the suitability of the technologyfor US plants and give confidence in its safety potential. To enhance user safety the system is beingproposed as a new igniter classification (a “Special” derivative of the existing Class II) which requiresthe usage to be under defined conditions only.

The key distinguishing characteristic between the igniter classes in the NFPA 85 code is thedifference in igniter ability to tolerate process variations. Based on the igniter ability to function underdifficult conditions, the implementation and the privileges of the igniter class vary. Whereas Class Ican be used under “all credible” conditions (3.3.73.1), Class II can be used under “prescribed”(3.3.73.2) light off conditions only.

The restriction to prescribed conditions is also required due to the difficulty in igniter flame proving in


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some of these applications for the plasma igniters form. The location of the igniter flame inside theburner barrel, where it cannot be reliably sensed with existing flame proving technologies, requiresthe use of a proven main burner flame under non initial start-up conditions for safe operation.

This revision will help avoid unsafe application of this new technology by providing clear andconsistent minimum safety requirements.

ResponseMessage:




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* Concentrated Flame IgntiterAn integrated burner-igniter system that utilizes either oil or gas to raise the pulveized coal stream to itsautoignition temperature.




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Committee Statement

CommitteeStatement:


---

Problem Statement


Substantiation




The restriction to prescribed conditions is also required due to the difficulty in igniter flame proving insome of these applications for the plasma igniters form. The location of the igniter flame inside the


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burner barrel, where it cannot be reliably sensed with existing flame proving technologies, requiresthe use of a proven main burner flame under non initial start-up conditions for safe operation.


ResponseMessage:




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3.3.73.xx * Plasma Arc IgniterAn integrated burner-igniter system that utilizes high temperature ionized gas to rapidly fracture coalparticles and ignite volatiles, as part of an integrated burner-igniter system.




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Committee Statement

CommitteeStatement:


---

Problem Statement


Substantiation




The restriction to prescribed conditions is also required due to the difficulty in igniter flame proving insome of these applications for the plasma igniters form. The location of the igniter flame inside the


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burner barrel, where it cannot be reliably sensed with existing flame proving technologies, requiresthe use of a proven main burner flame under non initial start-up conditions for safe operation.


ResponseMessage:




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First Revision No. 104-NFPA 85-2017 [ New Section after 3.3.76 ]

3.3.76.1 Permissive.

An interlock that functions only to allow initiation of the operation of equipment or a subsequent function.




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CommitteeStatement:

The definition for permissive has been revised to better represent how the term is usedthroughout the document. Additional First Revisions have been made to make usage consistent.

Public Input No. 28-NFPA 85-2016 [New Section after 3.3.76]


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3.3.76.2 Trip.

An interlock that shuts down equipment when a predefined set of conditions exists.




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CommitteeStatement:

The definition for trip has been revised to better represent how the term is used throughout thedocument. Additional First Revisions have been made to make usage consistent.

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3.3.76 Interlock.

A device, or an arrangement of devices, in which function which prevents, limits, stops, or initiates theoperation of one part or one mechanism of the device or arrangement controls the operation of anotherpart of another mechanism equipment or a subsequent function.

A.3.3.76

An interlock can consist of a sensing function, a control function, and an output or a final control element. The interlock can be accomplished with the use of any combination of electrical devices, mechanicaldevices, or logic .




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Committee Statement

CommitteeStatement:

The definition for interlock has been revised to better represent how the term is used throughoutthe document. Additional First Revisions have been made to make usage consistent.



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3.3.94 Permissive.

See 3.3.76.1.




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CommitteeStatement:

The definition for permissive has been added (3.3.76.1) to better represent how the term is usedthroughout the document. Additional First Revisions have been made to make usage consistent.

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3.3.119 Shutdown.

3.3.119.1 Combustion Turbine Normal Shutdown.

The normal sequence of events that automatically provides successful shutdown of the combustion turbinewith no abnormal conditions in the combustion system.

3.3.119.2 Normal Shutdown.

Stopping burner operation by shutting off all fuel and ignition energy to the combustion equipment.

3.3.119.3 Safety Shutdown (Single Burner Boiler).

Stopping burner operation by shutting off all fuel and ignition energy to the furnace.




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Committee Statement

CommitteeStatement:

The definition for Combustion Turbine Normal Shutdown contains requirements, which areprohibited in definitions by the NFPA Manual of Style. Language should be added to Chapter 8 tomaintain the requirement for no abnormal conditions prior to establishing purge credit.

The definition for Normal Shutdown is redundant to requirements already included in theequipment-specific chapters where normal shutdown sequences are described in detail.

The Single Burner Boiler definition for Safety Shutdown describes a Master Fuel Trip, which isdefined. The SBB Technical Committee can submit Public Comments on this action as they deemnecessary.

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3.3.127 Transmitter.

Any device that converts process measurements from a sensor into a variable signal to be received by adisplay, control, or protective device interlock .




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Committee Statement: This revision aligns with the revised definition for interlock (FR 103).

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3.3.129 Trip.

See 3.3.76.2.




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CommitteeStatement:

The definition for trip has been added (3.3.76.2) to better represent how the term is usedthroughout the document. Additional First Revisions have been made to make usage consistent.

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3.3.132.8 * Safety Shutoff Valve (Safety Trip Valve).

A An automatic fast-closing valve that automatically shuts off the gaseous or liquid fuel supply in responseto a normal, emergency, or safety shutdown signal. shutdown or trip signal.

A.3.3.132.8 The actua on values and me of ac on of the ini a on devices should be tuned to the furnace and

equipment on which they are installed. The me required for closing the valve should be selected to minimize the

possibility of equipment damage due to closing forces and hydraulic shock associated with rapid closure of large‐

diameter valves. Subject specific chapters must be consulted to determine if a specific me frame for valve closure

is required.




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Committee Statement

CommitteeStatement:

The types of shutdown signals were removed to be consistent with FR 105 which defines trip,and FR 112 that removes the definition of safety shutdown.

Annex material was added to clarify the term fast-closing and to signal to the user of the codethat other chapters should be referenced for specific closing speeds.

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Committee Input No. 153-NFPA 85-2017 [ New Section after 4.1 ]

A task group will be created at the end of this cycle to look at common requirements that can potentially bemoved to Chapter 4 in the next cycle. The Fundamentals Committee will be looking for Task Groupvolunteers from all BCS Committees.




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Committee Statement

CommitteeStatement:

A task group will be created at the end of this cycle to look at common requirements that canpotentially be moved to Chapter 4 in the next cycle. The Fundamentals Committee will be lookingfor Task Group volunteers from all BCS Committees.

ResponseMessage:

Public Input No. 172-NFPA 85-2016 [New Section after 4.1]


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4.2.4

The interlock system and protective devices shall interlocks and associated devices shall be tested jointlyby the organization responsible for the system design and by those who operate and operate or maintainsuch a system and devices .




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Committee Statement

CommitteeStatement:

This revision aligns with the revised definition for interlock (FR 103). Interlock system waspreviously undefined.

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Committee Input No. 154-NFPA 85-2017 [ New Section after 4.3.2 ]

4.3.3* The owner or fuel provider shall specify the lowest Autoignition Temperature (AIT) for all fuels firedin the boiler and/or combustion system over the range of the expected operating conditions taking intoconsideration fuel composition, pressure and oxygen concentration.

A.4.3.3 Autoignition temperatures for various materials can be found in Table 4.4.2 of 2017 NFPA 497,Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous(Classified) Locations for Electrical Installations in Chemical Process Areas. The value of autoignitiontemperature depends on the method of testing. The data provided NFPA 497 was developed usinginternationally accepted test methods. If a particular material is not included in this document, the dataobtained in a similar apparatus described by ASTM E659, Standard Test Method for AutoignitionTemperature of Liquid Chemicals, can be used.




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Committee Statement

CommitteeStatement:

There are numerous instances in Chapter 8 as well as in Chapter 6 that reference AutoignitionTemperature (AIT).

Natural gas is usually a mixture of various gases, with the primary component being methane. Asearch of the internet for “the Auto-ignition Temperature of Natural gas” gave the AIT of natural gas(methane) to be 580°C. NFPA 497 did not specify an AIT for natural gas but gave 600°C formethane. Additionally, many HRSG’s are in refinery service that can use “refinery” gas in thecombustion turbine and/or the duct burner where the AIT can vary depending on the blend.

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4.3.2*

The integration of the various components, including boiler or HRSG, burner, fuel and air supply equipment,controls, interlocks and safety and associated devices, operator and maintenance functions, andcommunication and training, shall be the responsibility of the owner and the operating company.




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Committee Statement

CommitteeStatement:

This revision aligns with the revised definition for interlock (FR 103). Safety devices areundefined.



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4.5.5

Interlock devices shall Interlocks shall be permitted to be temporarily removed from service in accordancewith the following:


(2) Alternate means shall be substituted to supervise this the interlock function in accordance withoperating procedures.




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Committee Statement

CommitteeStatement:

This revision aligns with the revised definition for interlock (FR 103). Interlock devices areundefined.

Response Message:



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4.7.7* Ignition Subsystem.

The ignition subsystem shall meet the requirements of 4.7.7.1 through 4.7.7.13.

4.7.7.1

The ignition subsystem shall be sized and arranged to ignite the main burner input within the limitation ofthe igniter classification as follows:

(1) It shall be verified through testing that the igniters furnished meet the requirements of the classspecified in the design.

(2) Igniters shall be designated as Class 1, Class 2, or Class 3 as defined in 3.3.73.1, 3.3.73.2, and3.3.73.3 and as verified by test.

4.7.7.2

Class 1 igniters shall be permitted to be used as Class 2 or Class 3 igniters. Class 2 igniters shall bepermitted to be used as Class 3 igniters.

4.7.7.3

Where Class 2 igniters are used, the burner shall be operated under controlled conditions to limit thepotential for abnormal operation, as well as to limit the charge of fuel in the event that ignition does notoccur during light-off.

4.7.7.4

Class 2 igniters shall not be used to ignite the main fuel under uncontrolled or abnormal conditions.

4.7.7.5

Where Class 3 igniters are used, the igniter shall be turned off as a part of the burner light-off procedurewhen the time trial for ignition of the main burner has expired, to ensure that the main flame is notdependent on ignition support from the igniter.

4.7.7.6

Class 2 igniters shall not be used to extend the turndown range but shall be permitted to be used tosupport ignition under low-load or adverse operating conditions.

4.7.7.7

Class 3 igniters shall not be used to support ignition or to extend the burner turndown range.

4.7.7.8

Except for periods when the main burner is being scavenged, Class 3 special igniters shall not be usedunless supervision of the individual main burner flame is provided.

4.7.7.9*

Where Class 1 and Class 2 igniters are used, the tests described in 6.6.3.2.2, 6.7.3.2.2, and 6.8.3.2.2shall also be performed with the ignition subsystem in service to verify that the igniters furnished meet therequirements of the class specified in the design.

4.7.7.10

Tests shall be performed to determine transient limits in the ignition air and fuel supplies or in the main airand fuel supplies that do not extinguish the igniter flame or reduce the igniter's ability to perform itsintended function or adversely affect other burners and igniters in operation.


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4.7.7.11

Igniters shall be permanently installed under the following conditions:

(1) They shall be supervised to verify that the requirements of 4.7.7.1 and 4.7.7.2 are met.

(2) This supervision shall include igniter capacity and individual igniter flame monitoring.

(3) The capacity shall be measured by igniter header pressure as a minimum.

(4) On single burner boilers, igniters shall not require supervision of igniter capacity.

4.7.7.12

The ignition equipment shall be located in an environment free of excessive heat and accessible formaintenance.

4.7.7.13

All igniter safety shutoff valves shall be located to minimize the volume of fuel that is downstream of thevalve in the individual igniter fuel lines or that could flow by gravity into the combustion chamber after anemergency shutdown or a burner shutdown.




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Committee Statement

CommitteeStatement:

The submitter of PI 133 has raised an important issue that illustrated differing interpretations ofthe material and allowances in 4.7.7 as a whole. A Task Group has been formed to review thissection and submit Public Comments.

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4.7.7.1

The ignition subsystem shall be sized and arranged to ignite the main burner input within the limitation ofthe igniter classification as follows:

(1) It shall be verified through testing that the igniters furnished meet the requirements of the classspecified in the design.

(2) Igniters shall be designated as Class 1, Class 2, Class 3 or Class 3 Special as defined in 3.3.73.1,3.3.73.2, and 3.3.73.3 and 3.3.73.4 and as verified by test.




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Committee Statement

CommitteeStatement:

4.7.7.1(2) as currently written would not allow the use of a "Class 3 Special Igniter" as a validIgnition Subsystem, although later in the paragraph (4.7.7.8) restrictions/conditions are given forthe use of a Class 3 Special Igniter.

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Committee Input No. 142-NFPA 85-2017 [ Section No. 4.7.7.10 ]

4.7.7.10 *

Tests shall be performed to determine transient limits in the ignition air and fuel supplies or in the main airand fuel supplies that do not extinguish the igniter flame or reduce the igniter's ability to perform its intendedfunction or adversely affect other burners and igniters in operation.

A.4.7.7.10 The Class 1 igniter design, and associated test plan, should address all credible combinationsof main burner inputs via first stating the high and low limits of those burner inputs, and then testing allcredible combinations of those burner input limits, including at least:

(1) Range of ultimate and proximate analyses of fuels to be fired

(2) Range of heat input from burner minimum to burner maximum

(3) Range of pulverized fuel product fineness entering the burners

(4) Range of coal/air (primary air) temperature entering the burner nozzle from the coal conduit

(5) Range of secondary air temperature

(6) Range of burner stoichiometric ratio, or burner air-to-fuel ratio




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CommitteeStatement:

Currently, there is no guidance on what type of tests need to be performed to verify the igniterclassification. This CI is to provides a starting point to review the issue. Public Comments areencouraged.

ResponseMessage:




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4.7.7.13

All igniter safety shutoff valves shall be located to minimize the volume of fuel that is downstream of thevalve in the individual igniter fuel lines or that could flow by gravity into the combustion chamber after anemergency shutdown or a burner shutdown.




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Committee Statement: This is a concern for any type of shutdown, not just an emergency or burner shutdown.

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First Revision No. 155-NFPA 85-2017 [ New Section after 4.10.1.1 ]

4.10.1.2 Overpressure Protection.

4.10.1.2.1

Overpressure protection shall be provided in either of the following cases:

(1) When the supply pressure exceeds the pressure rating of any downstream component

(2) When the failure of a single upstream line regulator or service pressure regulator results in a supplypressure exceeding the pressure rating of any downstream component

4.10.1.2.2

Overpressure protection shall be provided by any one of the following:

(1) A series regulator in combination with a line regulator or service pressure regulator

(2) A monitoring regulator installed in combination with a line regulator or service pressure regulator

(3)* A full-capacity pressure relief valve

(4) An overpressure cutoff device, such as a slam-shut valve or a high-pressure switch in combinationwith an adequately rated shutoff valve

4.10.1.2.3

When a relief valve is used to comply with 4.10.1.2.1 , the relief valve shall be a full-capacity relieftype.

4.10.1.2.4

Token relief valves and internal token relief valves shall not be permitted to be used as the onlyoverpressure protection devices.

4.10.1.2. 5 * Setpoint of the Overpressure Protection Device.

The overpressure protection device shall be set to provide a maximum downstream pressure as follows:

(1) When the rated pressure of any component is less than 12 psi (83 kPa), the set point of theoverpressure protection device shall not exceed 150 percent of the rated pressure of the lowest ratedcomponent.

(2) When the rated pressure of any component is equal to or greater than 12 psi (83 kPa) but less than 60psi (414 kPa), the set point of the overpressure protection device shall not exceed 6 psi (41 kPa) above therated pressure of the lowest rated component.

(3) When the rated pressure of any component is equal to or greater than 60 psi (414 kPa), the set point ofthe overpressure protection device shall not exceed 110 percent of the rated pressure of the lowest ratedcomponent.

A.4.10.1.2.2 (3 )

Upon upstream pressure regulation failure, a full-capacity pressure relief valve (versus token relief valves)will limit the downstream pressure. Token relief valves only provide minimum pressure relief in cases whereambient temperatures increase the pressure inside the gas piping, which can occur during shutdownperiods, or relieves small increases of pressure due to high lockup pressures that occur during a shutdown.


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A.4.10.1.2.5 The pressure limits in this section are consistent with 49 CFR Part 192.201,

Required Capacity of Pressure Relieving and Limiting Stations




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CommitteeStatement:

Overpressure protection is a common element in multiple subject chapters, therefore theFundamentals committee is moving it forward to Chapter 4. In addition, detail was added to clarifyapplication of overpressure protection and methods to achieve it.

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4.11.1 Interlock System Interlocks .

4.11.1.1

The basic requirement of an interlock system for a boiler or combustion system shall accomplish thefollowing interlocks shall :

(1) Protect personnel from injury

(2) Protect equipment from damage

(3) Protect operation by limiting actions to a prescribed operating sequence or by initiating a trip deviceswhen approaching an out-of-range or unstable operating condition

4.11.1.2*

Additional automatic trips interlocks shall be permitted.

4.11.1.3

Fuel-specific interlocks shall be provided for each design basis fuel.

4.11.1.4*

Operating personnel shall be made aware of the limitations of the interlock system interlocks .




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Committee Statement

CommitteeStatement:

This revision aligns with the updated and new definitions for interlock and trip. Interlocksystems are undefined.

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4.11.4

The burner management system interlock interlocks and alarm functions shall alarms shall be initiated byone or more of the following:

(1) One switch or transmitter dedicated to the burner management system

(2) Voting logic derived from two or more switches or transmitters

4.11.4.1 (a)

When multiple transmitters are used in the burner management system, such signals shall be permitted tobe shared with other control systems for control purposes.

4.11.4.2 (b) *

When signals from multiple switches or transmitters are provided to initiate interlock interlocks or alarmfunctions alarms , those signals shall be monitored in comparison to each other by divergence or other faultdiagnostic alarms.

4.11.4.3 (c)

When signals from multiple switches or transmitters are provided to initiate interlock interlocks or alarmfunctions alarms , the provided signals shall be generated by individual sensing devices connected toseparate process taps.




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Committee Statement

CommitteeStatement:

This revision aligns with the revised definition of interlock (FR 103).

The section was restructured because there was confusion about how they were to be applied.4.11.4.1 through 4.11.4.3 apply to the second list item under 4.11.4.

ResponseMessage:




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4.11.8.2

The burner management safety functions system shall include but shall not be limited to purge interlocksand timing, mandatory safety shutdowns, trial timing for ignition, and all required interlocks and flamemonitoring.




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Committee Statement

CommitteeStatement:

Safety functions were undefined, and there was some confusion around the shall/shall notlanguage. This revision clarifies what is intended for the independent burner managementsystem.

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4.11.9 Momentary Closing of Fuel Valves.

4.11.9.1

Logic sequences or devices intended to cause a safety shutdown, once initiated, shall cause a burner orA burner trip, fuel trip, or master fuel trip , as applicable, and shall require operator action prior to resumingoperation of the affected burner(s).

4.11.9.2 *

No logic sequence or device shall be permitted that allows momentary full closing and subsequentinadvertent reopening of the main or ignition fuel valves.

A.4.11.9.2 This is not meant to apply to partial stroke testing of fuel valves.




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CommitteeStatement:

This revision aligns with the new definition of trip (FR 105). It also removes the unenforceableterm "momentary" and clarifies the application of 4.11.9.2 with annex material.

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4.11.11 Documentation.

Documentation shall be provided to the owner and the operator indicating that all safety devices and logicmeet the the Burner Management System meets the requirements of the application.




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CommitteeStatement:

Safety devices are undefined. Safety devices and logic are all part of the burnermanagement system.

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4.12.1 Functional Requirements.

The basic requirements of any flame monitoring and tripping system shall be as follows:

(1) Combustion instability situations shall be brought to the attention of the operator for remedial action.

(2) An emergency shutdown A trip of the involved equipment shall be automatically initiated upondetection of serious combustion problems that will lead to the accumulation of unburned fuel.




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Committee Statement: This revision aligns with the new definition for trip created by FR 105.

Response Message:



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4.12.2 System Objectives.

4.12.2.1

System objectives shall be developed and documented that include those requirements that arespecifically related to the combustion conditions typical for particular combustion chamber configurations,burner or firing systems, and fuel characteristics.

4.12.2.2

Such objectives shall be consistent with the individual manufacturer's design philosophy.




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CommitteeStatement:

The revision has added a requirement to document the objectives to make this sectionenforceable.

Response Message:



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First Revision No. 125-NFPA 85-2017 [ Sections 4.13.2.1, 4.13.2.2 ]

Sections 4.13.2.1, 4.13.2.2

4.13.2.1*

Except as noted in 4.13.2.2 , under no circumstances shall airflow demand Airflow demand shall not beless than the minimum purge rate established by the designer.

4.13.2.2

For single burner boilers, airflow demand shall not be reduced below the low limit of the fuel-burningsystem as determined by the burner manufacturer and verified by operating test.




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Committee Statement

CommitteeStatement:

To better organize the document, this exception should be addressed by SBB in Chapter5.

Response Message:

Public Input No. 45-NFPA 85-2016 [Sections 4.13.2.1, 4.13.2.2]


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First Revision No. 126-NFPA 85-2017 [ Sections 4.13.3.3.1, 4.13.3.3.2 ]

Sections 4.13.3.3.1, 4.13.3.3.2

4.13.3.3.1

Except as noted in 4.13.3.3.2 , automatic Automatic control of the fuel input(s) shall not be permittedunless the airflow is maintained in automatic control.

4.13.3.3.2

For HRSGs designed and operated in accordance with Chapter 8 , automatic control of fuel inputs shallbe permitted without automatic control of airflow.




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Committee Statement

CommitteeStatement:

To better organize the document, this exception should be addressed by HRS in Chapter8.

Response Message:

Public Input No. 46-NFPA 85-2016 [Sections 4.13.3.3.1, 4.13.3.3.2]


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4.13.3.5

The combustion control system shall not reduce the fuel feed to a pulverizer below the minimum feed rateestablished by the pulverizer manufacturer for the manufacturer's specified design fuel.

4.13.3.5.1

For fuels with ignition characteristics different from those of the manufacturer's design fuel, the combustioncontrol system shall not reduce the fuel feed rate below the value that ensures stable and self-sustainingcombustion at the burners served by the pulverizer.

4.13.3.5.2

The minimum feed rate for fuels not conforming to the fuel specifications used by the manufacturer in thedesign of the pulverizer system shall be determined by operational tests.




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CommitteeStatement:

To better organize the document, the FUN TC has proposed that this topic should beaddressed by MBB in Chapter 6.

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First Revision No. 128-NFPA 85-2017 [ Section No. 4.14 ]

4.14 Power Supplies.

Precautions shall be taken to ensure the availability of a failure-free power supply (electric or pneumatic) toall control and safety devices burner management system components .




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Committee Statement

Committee Statement: Safety devices are undefined. This revision clarifies the applicability of the requirement.

Response Message:

Public Input No. 48-NFPA 85-2016 [Section No. 4.14]


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4.15.1

Except as noted in 4.15.1.1 and 4.15.1.2 , continuous Continuous trend display of steam flow rate,feedwater flow rate, total fuel flow rate, and total airflow rate as a percentage of the maximum unit load,drum level or waterwall flow as applicable , final steam temperature, main steam pressure, and furnace orcombustion chamber draft shall be simultaneously available at the operating location.

4.15.1.1 *

For single burner boilers, continuous trend display of operating parameters critical to operation shall beprovided.

4.15.1.2

For HRSGs, continuous trend display requirements are specified in 8.7.2.3 .




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Committee Statement

CommitteeStatement:

To better organize the document, these exceptions should be addressed by SBB in Chapter 5and by HRS in Chapter 8, including the associated Annex material.

Waterwall flow was added because not all boilers covered will have a drum level.

ResponseMessage:


Public Input No. 55-NFPA 85-2016 [Section No. A.4.15.1.1]


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First Revision No. 130-NFPA 85-2017 [ Section No. A.1.2.1 ]

A.1.2.1

Combustion explosions involve several considerations. The basic cause of uncontrolled fires or combustionexplosions is the ignition of an accumulated combustible mixture within the confined space of a furnace, aHRSG, or a pulverizer or the associated passes, ducts, and fans that convey the gases of combustion tothe stack.

A dangerous combustible mixture within the boiler, HRSG, or pulverizer enclosure consists of theaccumulation of an excessive quantity of combustibles mixed with air in proportions that result in rapid oruncontrolled combustion when an ignition source is supplied. An explosion can result from ignition of thisaccumulation if the quantity of combustible mixture and the proportion of air to fuel are such that anexplosive force is created within the enclosure. The magnitude and the intensity of the explosion depend onboth the relative quantity of combustibles that has accumulated and the proportion of air that mixes with thecombustibles at the moment of ignition. Explosions, including “puffs,” are the result of improper operatingprocedures by personnel, improper design of equipment or control systems, or malfunction of theequipment or control system.

Numerous conditions can arise in connection with the operation of a system that produce explosiveconditions. The most common of these are as follows:

(1) An interruption of the fuel or air supply or ignition energy sufficient to result in momentary loss offlames, followed by restoration and delayed reignition of an accumulation

(2) Fuel leakage into an idle combustion chamber and the ignition of the accumulation by a spark or othersource of ignition

(3) Repeated unsuccessful attempts to light off without appropriate purging, resulting in the accumulationof an explosive mixture

(4) The accumulation of an explosive mixture of fuel and air as a result of loss of flame or incompletecombustion and the ignition of the accumulation by a spark or other ignition source, such as couldoccur when an attempt is made to relight a burner(s)

(5) Purging with an airflow that is too high, which stirs up smoldering combustible materials

The listed conditions favorable to an explosion are typical examples, and an examination of numerousreports of explosions suggests that the occurrence of small explosions, puffs, or near misses has been farmore frequent than usually is recognized. It is believed that improved instrumentation, safety interlocks andprotective associated devices, proper operating sequences, and a clearer understanding of the problem byboth designers and operators can greatly reduce the risks and actual incidence of explosions.

In a boiler or a HRSG, upset conditions or control malfunction can lead to an air-fuel mixture that couldresult in a flameout followed by reignition after a combustible air-fuel ratio has been re-established.

Dead pockets might exist in a pulverized fuel system or in a boiler or HRSG enclosure or other parts of theunit, where combustible mixtures can accumulate under upset conditions. These accumulations could ignitewith explosive force in the presence of an ignition source.

Furnace or HRSG implosions involve another set of considerations. An implosion is the result of theoccurrence of excessively low gas side pressure, which causes equipment damage. Two conditions thathave caused implosions follow:

(1) A maloperation of the equipment that regulates the gas flow, including air supply and flue gasremoval, resulting in exposure to excessive induced draft fan head capability

(2) The rapid decay of gas temperatures and pressure resulting from either a rapid reduction in fuel inputor a master fuel trip

A combination of the two listed conditions has resulted in severe implosion incidents.



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Committee Statement

Committee Statement: This revision aligns with the updated definition of interlock.

Response Message:

Public Input No. 50-NFPA 85-2016 [Section No. A.1.2.1]


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A.3.3.25 Burner Management System.

The burner management system can include the following functions as specified in this code: interlocksystem interlocks , fuel trip system, master fuel trip system, master fuel trip relay, flame monitoring andtripping systems, ignition subsystem, main burner subsystem, warm-up burner subsystem, bed temperaturesubsystem, and duct burner system.




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Committee Statement

CommitteeStatement:

This revision aligns with the revised definition for interlock (FR 103). Interlock system waspreviously undefined.

ResponseMessage:



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First Revision No. 132-NFPA 85-2017 [ Section No. A.4.4.1.1 ]

A.4.4.1.1

An example of an inspection and maintenance schedule is as follows:

(1) Daily: flame failure detection system, low water level cutout, and alarm

(2) Weekly: igniter and burner operation

(3) Monthly: fan and airflow interlocks interlock device(s) , fuel safety shutoff valves for leakage, highsteam pressure interlock device(s) , fuel pressure and temperature interlocks interlock device(s) forfuel oil, high and low fuel pressure interlocks interlock device(s) , and fuel gas strainer and drip leg

(4) Semiannually: burner components; flame failure system components; piping, wiring, and connectionsof all interlocks and interlock devices and shutoff valves; calibration of instrumentation andcombustion control system




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Committee Statement

CommitteeStatement:

The definition of interlock revised by FR 103 indicates that interlocks are functions. The intentof this section is to inspect physical components.

ResponseMessage:



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First Revision No. 133-NFPA 85-2017 [ Section No. A.4.4.1.3 ]

A.4.4.1.3

When a system includes a built-in test mechanism that bypasses any safety device, it should beinterlocked interlock, the test mechanism should be designed to prevent operation of the system while thedevice is in the test mode, unless operation procedures specifically address this device or it is listed for thatpurpose.




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Committee Statement

Committee Statement: Safety devices are not defined. This revision aligns with the revised definition of interlock.

Response Message:



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A.4.11.7

Logic systems include, among others, programmable logic controllers (PLCs), digital processing units(DPUs process automation controllers (PACs ), and and distributed control systems (DCSs).




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Committee Statement

CommitteeStatement:

The term "digital processing units (DPUs)" is an old term that is rarely used and is not foundanywhere else in NFPA 85. PACs have come on the market over the last decade or so and are asort of a cross between PLCs and DCSs. This change to the Annex text would better reflect thecurrently available system technologies that might be utilized to implement burner managementsystems.

ResponseMessage:



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First Revision No. 134-NFPA 85-2017 [ Section No. A.4.13 ]


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A.4.13


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Users of this code are encouraged to use judgment in the application of the following guidelines for allprocess and safety functions contained in a distributed control system.

(1) For data transmission, the following should be considered:

(2) Every input should be sampled at intervals of no more than 1 second. Every output should beupdated at intervals of no more than 1 second.

(3) For protective actions, the system should be able to convert a changed input sensor value to acompleted output control action in 250 milliseconds or less.

(4) Changes in displayed data or status should be displayed within 5 seconds.

(5) Data acquisition and transmission systems should be protected from noise pickup andelectrical interference.

(6) In redundant systems, the data links should be protected from common mode failures. Wherepracticable, redundant data links should be routed on separate paths to protect against physicaldamage that disables both data links.

(7) For hardware, the following should be considered:

(8) The hardware selected should have adequate processor capacity to perform all the functionsrequired for start-up sequencing, normal operation alarming, monitoring, and shutdown of thecontrolled equipment. Capacity also should be available for data storage and sorting; thiscapacity can be permitted to be located in a separate processor.

(9) Selection should take into consideration the requirements for reliability, maintainability, andelectrical classification.

(10) The hardware should provide for automatic tracking between automatic and manual functionsto allow for immediate seamless transfer.

(11) The hardware should be capable of stable dynamic control.

(12) The hardware should be capable of thorough self-diagnosis.

(13) Consideration should be given to all levels and types of electrical interference that can betolerated by the hardware without compromising its reliability or effectiveness.

(14) Fail-safe operation should be obtained through a thorough and complete analysis of eachcontrol loop and by providing for a failure of that loop (i.e., valve/actuator) to cause a fail-safeposition.

(15) For software, the following should be considered:

(16) The software package should be designed to include all logic to provide a safe and reliablecontrol system. When the software calls for the operation of a

field safety device

(a) final control element , a feedback signal should be provided to prove that the requestedoperation has taken place, and an alarm should be actuated if the action is not confirmed in aspecified amount of time.

(b) The software package should be checked to ensure that no unintended codes or commandsare present (e.g., viruses or test breaks). The software package should be tested and practicedbefore being loaded into the plant site computers or processors.

(c) The software system should be protected from inadvertent actions by operators and should betamperproof.

(d) Written procedures should specify the functions that can and cannot be accessed by theoperator and those functions that require additional authorization for access.

(e) The software should be permitted to provide for authorized on-line changes of the timers andset points, provided the safety of the operating equipment is not compromised.

(f) The software should implement and enhance the self-diagnostic hardware.


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Street Address:

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Committee Statement

Committee Statement: Safety device is undefined and final control element is a generally understood term.

Response Message:

Public Input No. 54-NFPA 85-2016 [Section No. A.4.13]


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Committee Input No. 152-NFPA 85-2017 [ Chapter K ]

Annex K Informational References

K.1 Referenced Publications.

The documents or portions thereof listed in this annex are referenced within the informational sections ofthis code and are not part of the requirements of this document unless also listed in Chapter 2 for otherreasons.

K.1.1 NFPA Publications.

National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169-7471.

NFPA 30, Flammable and Combustible Liquids Code, 2015 edition.

NFPA 31, Standard for the Installation of Oil-Burning Equipment, 2011 edition.

NFPA 51, Standard for the Design and Installation of Oxygen–Fuel Gas Systems for Welding, Cutting, andAllied Processes, 2013 edition.

NFPA 51B, Standard for Fire Prevention During Welding, Cutting, and Other Hot Work, 2014 edition.

NFPA 54, National Fuel Gas Code, 2015 edition.

NFPA 56, Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable GasPiping Systems, 2014 edition.

NFPA 58, Liquefied Petroleum Gas Code, 2014 edition.

NFPA 68, Standard on Explosion Protection by Deflagration Venting, 2013 edition.

NFPA 69, Standard on Explosion Prevention Systems, 2014 edition.

NFPA 70 ®, National Electrical Code ®, 2014 edition.

NFPA 77, Recommended Practice on Static Electricity, 2014 edition.

NFPA 85, Boiler and Combustion Systems Hazards Code, 2007 edition.

NFPA 85, Boiler and Combustion Systems Hazards Code, 2011 edition.

NFPA 241, Standard for Safeguarding Construction, Alteration, and Demolition Operations, 2013 edition.

NFPA 497, Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and ofHazardous (Classified) Locations for Electrical Installations in Chemical Process Areas, 2012 edition.

NFPA 499, Recommended Practice for the Classification of Combustible Dusts and of Hazardous(Classified) Locations for Electrical Installations in Chemical Process Areas, 2013 edition.

NFPA 850, Recommended Practice for Fire Protection for Electric Generating Plants and High VoltageDirect Current Converter Stations, 2015 edition.

K.1.2 Other Publications.

K.1.2.1 ABMA Publications.

American Boiler Manufacturers Association, 8221 Old Courthouse Road, Suite 202 380 , Vienna, VA22182–3839 22182 .

ABMA 203, A Guide to Clean and Efficient Operation of Coal-Stoker-Fired Boilers, 2002.

ABMA 307, Combustion Control Guidelines for Single Burner Firetube and WatertubeIndustrial/Commercial/Institutional Boilers, 1999.

K.1.2.2 AlChE Publications.

American Institute of Chemical Engineers, 120 Wall Street, FL 23, New York, NY 10005-4020.

Guidelines for Hazard Evaluation Procedures, 2008.


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K.1.2.3 API Publications.

American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005-4070.

API STD 620, Standard for Design and Construction of Large, Welded, Low-Pressure Storage Tanks,2009 2013 .

API STD 650, Standard for Welded Steel Tanks for Oil Storage, 2008 2013 .

API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at PetroleumFacilities Classified as Class I, Division 1 and Division 2, 1998 (reaffirmed 2002) 2012 .

API RP 505, Recommended Practice for Classification of Locations for Electrical Installations at PetroleumFacilities Classified as Class I, Zone 0, Zone 1, and Zone 2, 1997 (reaffirmed 2002 2013 ).

API RP 2003, Recommended Practice for Protection Against Ignitions Arising Out of Static, Lightning, andStray Currents, 2008 2015 .

K.1.2.4 ASME Publications.

American Society of Mechanical Engineers, Two Park Avenue, New York, NY 10016-5990.

ASME Boiler and Pressure Vessel Code, 2007 2015 .

K.1.2.5 ASTM Publications.

ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.

ASTM D409/D409M , Standard Test Method for Grindability of Coal by the Hardgrove-Machine Method,2012 2016 .

ASTM D396, Standard Specification for Fuel Oils, 2009 2016 .

ASTM E1226, Standard Test Method for Explosibility of Dust Clouds, 2010 2012a .

K.1.2.6 EEMUA Publications.

The Engineering Equipment and Material Users Association, 63 Mark Lane, London UK EC3R 7NQ.

EEMUA Publication 191, Alarm Systems — A Guide to Design, Management, and Procurement, 20072013 .

K.1.2.7 IEC Publications.

International Electrotechnical Commission, 3, rue de Varembé, P.O. Box 131, CH-1211 Geneva 20,Switzerland.

IEC 61511, Functional Safety — Safety Instrumented Systems for the Process Industry Sector, 2003.

K.1.2.8 ISA Publications.

International Society of Automation, 67 T. W. Alexander Drive, Research Triangle Park, NC 27709.

ANSI/ISA 18.2,Management of Alarm Systems for the Process Industries, 2009.

ANSI/ISA 77.41.01, Fossil Fuel Power Plant Boiler Combustion Controls, 2005 2015 .

ANSI/ISA 77.42.01, Fossil Fuel Power Plant Feedwater Control System — Drum Type, 1999(R2006 reaffirmed 2011 ).

ANSI/ISA 77.43.01, Fossil Fuel Power Plant Unit/Plant Demand Development — Drum Type, 2002(R2008) , 2014 .

ANSI/ISA 77.44.01, Fossil Fuel Power Plant — Steam Temperature Controls, 2007 (reaffirmed 2013) .

ANSI/ISA 84.00.01, Application of Safety Instrument Systems for the Process Industry, 2004.

ISA TR18.2.4, Enhanced and Advanced Alarm Methods, 2012

ISA TR18.2.5, Alarm System Monitoring, Assessment, and Auditing, 2012.

K.2 Informational References.

The following documents or portions thereof are listed here as informational resources only. They are not apart of the requirements of this document.


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K.2.1 Additional HRSG References.

The following documents provide additional information on iron fires.

Johnson, A. A., J. A. Von Franuhofer, and E. W. Jannett,“Combustion of Finned Steel Tubing During StressRelief Heat Treatment,” Journal of Heat Treating, Vol. 4, No. 3, June 1986, pp. 265–271.

McDonald, C. F., “The Potential Danger of Fire in Gas Turbine Heat Exchangers,” ASME 69-GT-38.

Theoclitus, G., “Heat Exchanger Fires and the Ignition of Solid Metals,” Journal of Engineering for GasTurbines and Power, Vol. 107, July 1985, pp. 607–612.

K.3 References for Extracts in Informational Sections.

NFPA 69, Standard on Explosion Prevention Systems, 2014 edition. .




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Committee Statement

CommitteeStatement:

The committee will review the referenced documents at the second draft meeting so that theywill have a more timely picture of what has been updated since the last edition was issued.

ResponseMessage:

Public Input No. 242-NFPA 85-2017 [Section No. K.1.2.5]


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technical committee on single burner boilers nfpa 85 … · bcs-sbb joseph e. fehr principal sega,...

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