safe work practices on line breaking

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KUWAIT NATIONAL PETROLEUM COMPANY

Reference: SHE-TSSA-07-2026 ( Rev 0) Title: SWP on Line Breaking Date of Issue: June 2007

SAFE WORK PRACTICES ON

LINE BREAKING

TABLE OF CONTENTS

# Page 1.0 INTRODUCTION 3 2.0 SCOPE 3 3.0 REFERENCES 3 4.0 DEFINITIONS 4 5.0 STANDARDS/GUIDELINES 6 5.1 NEW PROJECTS AND MODIFICATIONS TO EXISTING

SYSTEMS 6

5.2 TRAINING 7 5.3 JOB PLANNING 7

5.4 SYSTEM PREPARATION 8 5.5 LOCKOUT/ISOLATION 8

5.6 JOB EXECUTION 9 6.0 HAZARDS ON WORKING ON FLARE LINES 12 6.1 SOURCE OF AIR 12 6.2 PRECAUTIONS 13 6.3 ADDITIONAL INFORMATION 14 7.0 INCIDENT INVESTIGATION 14 8.0 MANAGEMENT SYSTEMS 14

8.1 DOCUMENT CONTROL 14 8.2 AUDIT REQUIREMENTS 14 8.3 DOCUMENT RENEWAL PROCESS 15 8.4 DEVIATION PROCESS 15


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1.0 INTRODUCTION

Spreading of flange joints, disconnecting unions and removing spool pieces or

bends in process and utility lines are required during most maintenance activities

and tie-in related to project activities. Accidents have occurred due to negligence of

safety aspects during such jobs. All parties involved in such jobs shall ensure

appropriate precautions. 2.0 SCOPE

To provide the minimum provisions for planning and executing all line breaks and

to specify the line break considerations to be addressed at an early stage in the

design process of new and modified equipment.

Mandatory rules are characterized by the word “SHALL” throughout the text.

Advisory rules or recommendations are indicated by the word “SHOULD”. The

words shall and should have been used to remain in line with the terminology used

by the American National Standards Institute.

Various designations mentioned in the document are refinery based. Equivalent

designations shall be applicable for other locations/ sites.

3.0 REFERENCES

− KPC HSE Document No. 24; Line Break Procedure

− Maintenance Work Practices; Lock-Out/Tag-Out KNPC-SMM-1-PRC-

0403.

− Maintenance Work Practices; Zero Energy Test KNPC-SMM-1-PRC-0404

− Procedure for Multi-Lock System in Refineries MAA-ELAC-03-1330

− PPE Program SHE-TSOH-04-1315.

− KNPC Design Engineering Practices

− SWP on Work Permit & Risk Assessment SHE-TSSA-06-2029

− SWP on Plant Operations SHE-TSSA-05-2002

− SWP on Confined Space Entry SHE-TSSA-04-SP-2007


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4.0 DEFINITIONS

4.1 Cleared—all lines and equipment associated with a system are verified by

standard practices to have been positively isolated and, where appropriate,

drained, flushed, and/or purged of hazardous material, and made ready for

hotwork as applicable and the following criteria are met:

− The system’s temperature is lower than 140°F (60°C) and higher

than 14°F (-10°C).

− Atmospheric pressure has been attained.

− Hazards associated with toxicity, corrosiveness, flammability of

gases, vapors, or mists, and/or airborne combustible dust are

reduced to acceptable levels, that is meeting normal operating

conditions.

4.2 Controlled bleed—a valved opening (bleed) located between two block

valves. The bleed consists of an open block valve and terminates with an

open end or pressure gauge. The bleed serves as an indicator of the

integrity of the upstream block valve. Selection and positioning of the bleed

termination point are dependent on the hazards associated with the

process material and local conditions at the time of the line break.

4.3 Double isolation—double block valve and controlled bleed (i.e., block

valve/controlled bleed/block valve) or block valve and blank/blind flange.

4.4 Engineered process plug—a means of isolating process flow by

solidifying a portion of the process in a pipeline in a controlled, pre-

designed, and approved manner.

4.5 Front-end loading—design activities before final design and approval

executed to uncover possible hidden problems and expense. 4.6 Hazardous process or system—a process or system that contains any

material at any pressure that could cause an injury to an individual(s), a

possibility of fire or explosion, an environmental hazard, or an off-site

hazard. Examples of hazardous processes or systems include, but are not

limited to, compressed fluids, especially gases in pipes and vessels;

corrosive and/or flammable substances; and other lines that could contain


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material that is hazardous on contact or inhalation, including fluid whose

temperature is higher than 140°F (60°C) or lower than 14°F (-10°C).

4.7 Isolation—Complete obstruction and elimination of flow to system (piping or equipment) ensuring full protection against the release of fluid

to the system by means such as blinding, removal of section of piping

(along with blinding the live end), double block and bleed system, manually

valved and/or blanked or blind flanged etc to completely isolate the line or

equipment from the process material and documented such isolation by

blind lists and locations clearly identified by tags.

4.8 Line break—opening cleared or uncleared lines or equipment that has

contained any fluid at a volume, pressure or temperature capable of

causing injury or damage to property by actions that may include, but are

not limited to, the following:

− Breaking flanges

− Removing one or more bolts from flanges

− Removing valve bonnets and non-return (i.e., check) valves

− Turning spectacle plates (i.e., blanks)

− Breaking pipe joints

− Removing slip plates (i.e., blanks), instrument orifice plates, blind

flanges, plugs, and caps

− Disconnecting tubing

− Disconnecting loading and unloading process hoses

− Penetrating a line by mechanical or other means

− Opening inspection ports

− Making subtle adjustments (e.g., replacing packing on a valve)

4.9 PPE—Personal Protective Equipment.

4.10 Qualified personnel—those who by extensive knowledge, training, and

experience have successfully demonstrated their ability to solve or resolve

problems related to line breaks in accordance with this document.


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5.0 STANDARDS/ GUIDELINES 5.1 NEW PROJECTS AND MODIFICATIONS TO EXISTING SYSTEMS

Operations Dept.,/ Process Engg. Division shall work with Asset Custodian

Dept/ Division during the design and engineering stages of a project so that

line break issues are considered in both new projects and modifications to

existing systems. Systems shall be designed and built to enable isolation

and clearing of the hazard. The following points shall be considered:

1. Isolation and clearing shall be primary considerations during project

front-end loading activity.

− The design shall consider the balance between added potential

leak points (catastrophic and fugitive) vs. the benefit of providing

additional connections for flushing and clearing access to systems

and equipment.

− The design shall include the ability to isolate secondary energy

sources for polymer and melt systems where the material is

“frozen” (i.e., solidified) to eliminate the hazard.

− All systems shall be designed with the ability to isolate secondary

energy sources. Examples of secondary energy sources include

steam and electric tracing and jacketed vessels and pipe.

2. Experienced field operators and mechanics shall be involved in the

front-end loading efforts.

3. The design team shall consider the following hierarchy for isolating

hazardous processes. The decision should be based on the level of

protection to people and environment vs. additional hazards

introduced as the result of adding additional valves.

a. Double block valve and controlled bleed

b. Block valve and blank/blind flange

c. Double block valves

d. Single block valve

e. Engineered process plug (i.e., solidifying the process)

If neither double block valve and controlled bleed or block valve and

blank/blind flange isolation is feasible, then appropriate safeguards


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(for example regular testing of single valves) shall be provided,

documented, and included as a part of the Hazop study.

5.2 TRAINING Team Leader of the Executing Dept shall ensure that qualified personnel

perform all work on hazardous processes or systems, including planning and

execution. Team Leaders of Executing and Asset Custodian Departments shall

also ensure that training is provided to persons involved on line break

procedures. The topic shall be included in the SHE training program at SHE

Training Center.

Key elements for determining personnel qualifications are listed below:

1. Initial training shall be provided for

− Operating personnel, including supervisors.

− Maintenance and construction personnel, including supervisors.

− Contractors and contract administrators.

− Planners/schedulers.

− Personnel who issue line break permits.

2. Refresher Training shall be provided every 3 years.

3. Training shall be documented.

4. There should be a system to check that the training had been

effective.

5.3 JOB PLANNING 1. A written Risk Assessment that specifically addresses safety,

health, and environmental issues shall be prepared and

implemented for all line breaks on hazardous processes and

systems. This shall be as per document: SHE-TSSA-06-2029 SWP

Work Permit & Risk Assessment.

2. A line break permit shall be issued and precautions as per the Risk

Assessment shall be mentioned in the Permit.

3. Personnel performing the work shall be made aware of the safety,

health, and environmental requirements. The Issuer and Executor

shall ensure that the plan details are communicated to all the


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personnel involved. These details include lockout points, flushing

and clearing, and standby person responsibilities.

4. Team Leaders of the Custodian and Executing Dept shall ensure

that a process is in place to do the following:

a. Periodically review the Risk Assessment for inclusion of all

mandatory requirements of this document.

b. Document the line break training and periodic retraining of the

people performing the routine line break jobs 5.4 SYSTEM PREPARATION The system must be properly prepared before line breaks are made on any

system. Key elements for proper system preparation include establishing and

verifying acceptable levels of cleanliness, elimination and verification of

chemical hazards. The clearing and draining of pipelines and equipment must

follow approved waste management procedures to protect the environment.

5.5 LOCKOUT / ISOLATION All systems prepared for line breaks shall be properly isolated.

The following documents shall serve as a guideline in this regard

- Maintenance Work Practices; Lock-Out/Tag-Out KNPC-SMM-1-PRC-0403.

- Maintenance Work Practices; Zero Energy Test KNPC-SMM-1-PRC-0404

- Procedure for Multi-Lock System in Refineries MAA-ELAC-03-1330

- KNPC Blinding Deblinding Procedure

The following points shall be considered in isolation:

1. Tagging procedure: Systematic tagging of blinds used for positive

isolation of lines and equipment. Blanks and blind flanges shall be

tagged as described in the above document.

2. The bleed (drain/ vent) valve (for block & bleed) for the isolated system

shall be maintained in the open position and the line cleared to prevent

trapping process material in the line/equipment.

3. The specific steps for isolating all primary and secondary (e.g., steam

tracing, electric tracing, cathodic protection etc) energy sources shall be

identified.


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This is especially important in polymer and melt systems that are

“frozen” (i.e., solidified) to isolate them and for acids that can vaporize if

cooled and then reheated.

4. Various means of isolating systems or equipment that contain hazards

can be used. A listing, from the most protective to the least protective, is

given under 5.1 (3).

Examples of manual valves used for isolation are gate valves, plug

valves, and ball valves. The use of control valves for isolation is not

allowed.

5. The degree of isolation depends on the hazards of the material being

isolated, the surrounding area (including its electrical classification), the

configuration of the piping system, the frequency of the line break, the

added chance of leaks from additional isolation valves, and the

experience gained from past line breaks.

6. Where work on hazardous systems is to be performed behind a single

blocking valve, the line break permit or procedure shall indicate how the

hazard is to be mitigated, including worst-case scenarios and

contingency plans.

5.6 JOB EXECUTION The first break does not always verify that the system or equipment is free of

hazard. Experience has shown that incidents still occur after the first break is

completed. These incidents have a variety of causes, including trapped pockets

of pressure or hazardous process material, not isolating all sources of pressure

or hazardous process material, or not draining the low point and venting the

high point.

The following documents shall be referred for further guidance.

- SWP on Work Permit System and Risk Assessment;SHE-TSSA-06-2029

- SWP on Confined Space Entry:SHE-STSA-04-SP-2007

- SWP on Plant Operations: SHE-TSSA-05-2002 Rev 1 (Sec 8: Safe Operating

Practices)

1. Permit issuer shall ensure that the system is properly prepared before

any line breaks are made. If clearing cannot be accomplished as


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expected, the job shall be stopped and the following steps shall be

performed: re-plan, document, authorize, and communicate.

2. Maintenance personnel should never break a line without obtaining a

work permit from the Operations Supervisor. The work should proceed

only after Operations has clearly identified the flanges that are to be

opened.

3. Presence of permit issuer is essential at the work site during the

commencement of line break and also during lining up after completion

of job.

4. All parties involved in the line breaking shall be made aware of the

status of the equipment and the hazards involved.

5. Proper protective clothing and equipment are worn if toxic, corrosive or

other harmful substances could be present.

6. Lines and equipment are drained or depressurized of all possible

contents of flammable, corrosive liquid and toxic contents or

asphyxiating gas before opening.

7. Operations supervisor assures to the Maintenance personnel that

there are no naked lights, fires or other sources of ignition within 15m

radius, especially downwind of the line of the equipment to be opened.

Hot work Permits shall not be issued within this radius.

8. Ensure that both sides of the flange are properly supported/anchored

to avoid falling or spring action.

9. Workers should remain upwind, loosen the bolts without fully removing

them and spread the joint slightly to check that it has no pressure.

10. The area shall be barricaded to warn people not involved in the line

break of any unexpected release of hazardous material.

11. The location shall be monitored continuously for presence of toxic or

flammable gases if required by the permit. Necessary monitoring

equipment shall be available at site.

12. Note the location of safety shower before commencing work on

chemical lines.


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13. The joint shall be opened very slowly to ensure that there is no hold-up

of gas or liquid and that block valves are holding.

14. Slacken the bolts farthest away from the person first. Do not remove

the last bolt until inserting a wedge at far end to remove any remaining

content. Work above the flange and not below.

15. Precautions are taken to contain the leftover material/sludge and

minimize spillage. (providing drip tray, diking, etc)

16. Waste management guidelines issued by Environment Division shall

be followed in the handling and disposal of waste.

17. If it appears that the line is under pressure, the joint should be closed

immediately and reopened only under the direction of Operations

supervisor after corrective action has been taken. In such cases the

job plan shall be reviewed. The Risk Assessment will have to be

reviewed again before proceeding further in such cases.

18. Use non-sparking tools when working on hydrogen, ethylene,

acetylene and carbon disulphide lines.

19. Lines or vessels shall be considered full or hazardous until proven safe

for work

20. When work spans over two shifts the next shift people shall be made

aware of the ongoing job.

21. Steam Lines: It is possible that there could be presence of

hydrocarbons in steam lines. This occurs when process units are

subjected to emergency shutdowns including the steam system. This

could create vacuum conditions in the steam line sucking in

hydrocarbons. It is therefore advisable to conduct gas tests during

blinding/ deblinding of steam lines also.

22. Other Utility Lines: (Plant Air, Instrument Air, Nitrogen line, Water

lines including Sea Water). All utility lines shall be considered as

hydrocarbon contaminated. Gas tests shall be conducted during

spreading of the flange and precautions & procedures determined

accordingly.


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23. Modified Blinds: Large volatile hydrocarbon lines with passing valves

shall be blinded with modified blinds which have a

draining/depressurising connection especially when the system is

under pressure beyond the isolation valve. Content between valve and

the blind shall be emptied before deblinding.

24. Double Block & Bleed: Some high pressure or hazardous content

lines are provided with two block valves separated by a spool piece

that has a bleed connection vented to a safe location. Any passing

material will be vented instead of reaching the danger end.

25. Unions: Inserting a disc between union faces is not considered as

positive isolation. Union shall be disconnected and capped/plugged at

the danger end.

26. Blinds that were in position for a long time should be removed and

inspected before being used as positive isolation.

27. When taking into service, the system shall be checked at full operating

conditions, for example hot bolting where required.

6.0 HAZARDS OF WORKING ON FLARE LINES

Work on flare lines is far more susceptible to mishaps than are most other plant

piping arrangements. Hazards associated with such work and means of carrying

out the work safely are mentioned below

6.1 SOURCE OF AIR: Keeping air out of a flare system is of paramount importance. Air is most

likely to find its way into a flare system in one of the following ways:

1. Through open vents, drains or other connections

2. When flare lines are opened for maintenance or other system repair

3. While venting equipment (for example during start-up) into the flare

system

4. By the rapid condensation of hot vapour inducing a vacuum and

pulling air back into the system through the flare stack and seal.

5. Air is most likely to enter when a section of the system is to be gas

freed to permit 'hot work' on lines or equipment in preparation for


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entering system vessels or in connection with work on the flare and

its auxiliaries. A combustible mixture can reach the flare during

blinding or gas freeing of lines.

6.2 PRECAUTIONS

Flare lines should be purged with steam or inert gas before connected

equipment or lines are opened (i.e. before permitting entry of air).

Purging is especially important as flare streams contain H2S or

pyrophoric iron sulfide deposits providing an ignition source when air is

admitted.

The procedures given below shall be followed during shutdown and

maintenance activities:-

1. Shutdown all units serviced by the flare system before the flare is

taken out of service or else line up standby flare system if available.

2. Replace sweep gas with purge gas and continue until all system

bleeders test as safe.

3. Ensure that purge gas gets into all laterals in a complex flare

system, not just to the main collection header.

4. Extinguish flare pilot.

5. Blind all flare header inlets from the units as per the blind list and

notify all concerned personnel of the system's status.

6. All personnel during blinding/deblinding jobs shall wear airline

masks or SCBA and fire retardant clothing.

7. Purge gas shall be maintained at all times during the blinding

operation.

8. All mobile equipment shall be located upwind wherever possible.

9. Proper access facilities and work platforms shall be provided. More

than one ladder shall be provided to work platform as a means of

emergency escape.

10. Water spray systems and other fire protection shall be available at

location. A continuous water curtain shall be provided between

work area and adjacent operating refinery units.

11. All connected unit personnel are alerted before the start of the job.


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12. All material are available on site before work starts.

13. Sufficient bolts shall remain while a gradual opening is made by the

use of a flange spreader.

14. Once work has begun, continue without stopping until the job is

completed.

6.3 ADDITIONAL INFORMATION 1. Even with pilots extinguished and no pyrophoric material present, auto-

ignition still can occur so long as oxygen is present.

2. Hydrogen and hydrogen sulfide are especially hazardous due to their

broad flammability limits in air 4-74% and 4-45% respectively.

3. Lines from knockout drums to flare stacks and the flare stacks

themselves should drain back by gravity to the knockout drum.

4. While water washing of flare lines and KOD, hydrogen sulfide and

ammonium salts are released. It is possible that units and facilities get

contaminated with hydrogen sulfide as this wash water is carried en-

route to Waste Water Treatment facilities.

7.0 INCIDENT INVESTIGATION All line break incidents shall be investigated according to KNPC Incident

Investigation Procedure.

8.0 MANAGEMENT SYSTEMS

8.1 DOCUMENT CONTROL Records shall be retained in compliance with the KNPC Document Control

Programme. The contact for this document is the KNPC SH&E Department.

8.2 AUDIT REQUIREMENTS

Compliance with this document shall be audited as part of SHEMS audit

program.

8.3 DOCUMENT RENEWAL PROCESS This document shall be reviewed and revised by KNPC SHE Dept as

necessary and, at a minimum, not later than three years from the date of the

last revision.


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8.4 DEVIATION PROCESS Deviations from this document shall be authorised by the Manager SH&E.

Deviations shall be documented, and documentation shall include the

relevant facts supporting the deviation decision. Deviation authorization shall

be renewed periodically and no less frequently than every three years.


safe work practices on line breaking

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