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7/25/2019 Weir Valves

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Operating Experience Report (OPEX)

For

TRICENTRIC

Valves

Containment Purge & Vent Systems

Rev. Originator: Title: Signature: Date:

0 Gregory Green Nuclear Applications 12/6/2012


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OPEX INDEX

Index........................................................................................................................................... 2

Heritage...................................................................................................................................... 3

Equipment Description............................................................................................................. 3

Key Features and Benefits ....................................................................................................... 5

References for Purge & Vent Containment Isolation Valves................................................. 6

Partial Test List ......................................................................................................................... 6

Product Updates ....................................................................................................................... 6

General Design Description - Valve Assembly....................................................................... 8

Component Assembly Outline Drawings................................................................................ 9

Installation List........................................................................................................................ 11


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Heritage:

The TRICENTRIC Butterfly valve has a longhistory within the U.S. Nuclear market. Sincethe early 1960s, Clow Engineered Products soldquarter turn isolation valves to thepetrochemical, refining, steel and nuclearindustries. Their specialty application was forsevere service water. The triple offset valve wasrecognized as well designed, of high quality andextremely dependable.

In 1975, Clow secured an N & NPT stamp,and began an extensive engineering and testingprogram to upgrade the product while drivingdown costs. By 1982, the company was poisedto pursue the Nuclear Power Industry as its mainobjective.

Clow was sold to C&S Valve Company, in 1985,in a management buyout. Many long termemployees stayed and C&S increased itsnuclear installation base while offering anunheard of five (5) year warranty. Atwood &Morrill Company, a long time valve supplier withlineage dating back to the Nautilus nuclearsubmarine, acquired C&S in 1995 through anasset purchase. Key engineering,

manufacturing and sales employees were againretained and relocated to its Salem, MA factory.

The TRICENTRICname flourished with A&Muntil 2003 when the Weir Group, parentcompany of Atwood & Morrill, branded all itsvalve companies under a new Division calledWeir Valves & Controls where this industry

leading brand remains today.

Equipment Description:

Valves supplied for Containment Purge & VentValve Systems are TRICENTRIC valves.TRICENTRIC valves are triple offset metal

force between seat and seal and without anysliding, rubbing or interference. This accountsfor the high cycle life of these valves.

The sealing capability of the TRICENTRICvalve is achieved by an applied torque to thevalve stem. This torque is translated into acompressive force between the disc seal andthe valve seat. Thus, the valve leakage is

inversely proportional to the input torque. Inaddition, the geometry of the valve is such, thatthe differential pressure across the closed discassists closure of the disc. At a specificdifferential pressure, the differential pressurealone (without the aid of the actuator) willprovide the sealing capability of the valve.

These torque seated valves have been installedin virtually every nuclear power plant in the USAand throughout the world. They have beensuccessfully applied for temperature ranges ofcryogenic to 1600F and pressures from vacuumto 1400 psi.


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By having a conical seat profile with exactmatching seal profile and by offsetting therotational pivoting point of the disc in three (3)different directions, a triple offset valve is born.

Shaft Offset #1:Offset from the vertical sealingplane. Provides a pivot location for non-interference disc rotation and non-interruptedsealing surface (See Figure 1)

Shaft Offset #2:Shaft centerline is offset fromthe horizontal seal axis. Provides pivot locationfor camming action of the disc and createspressure area torque which helps energize theseal by increasing the contact force betweenseat and seal. (See Figure 1)

Shaft Offset #3: Centerline axis of the seal

surface is offset from the cone axis centerline.This is crucial for providing proper disc travelpath to the seat for contact at one point in thefully closed position. Also provides rotationaloperation without any seat to seal interference.(See Figure 1)

The disc rotation of this valve is achieved by anexternal mechanical torque producing device.This device (actuator) can be either a:

mechanical gear electric motor

pneumatic operated

Depending upon the type of actuation required,the valve assembly can be supplied to fail as is,fail closed or fail open.

As mentioned above, the sealing capability ofthis valve is achieved by a compressive forcebetween the disc seal and the valve seat whichrequires the valve to be torque seated and notposition seated. When the output torque of theactuating device causes the disc to rotate to thefully closed position, it is the valve seat thatlimits further disc rotation and not external oractuator adjustment stops. This characteristic ofthe valve assures that it will always provide apositive shutoff independent of any degradationof any thermal gradients. (See Figure 2 above)

Manufacturing requires standard machiningpractices, best achieved with CNS machining.

Figure 2 - Closed Position Seating ShowingDisc Seal Stack with Laminations


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TRICENTRIC valves have been used in Purge& Vent applications in both BWR and PWR

units. During this 25 year period, this valvedesign has proven to be the best engineeredvalve for this demanding application.

As a testament to the TRICENTRIC valve, it isthe only design used in every post-TMI U.S.OEM Purge & Vent valve replacement project.Just as noteworthy, the TRICENTRIC valve hasnever been replaced and offers industry leading

LLRT leakage performance. There are othertriple-offset valve designs in this market;however, no other triple-offset valve has theinstallation experience of the TRICENTRICinContainment Isolation applications and no othermanufacturer has the required knowledge &testing necessary for a successful change out inthis extremely demanding application.

Comprehensive description of the assembly,disassembly, maintenance and operation ofthese valves may be found in the Installation,Operation and Maintenance Service Manualprovided with these valves. The maintenancehistory for a triple offset valve is below average.Its robust design, with metal-to-metal seats andminimal soft goods, makes for easy

maintenance compared to resilient seatedbutterfly valves which require constant soft seatmaintenance and experience above averageleakage issues. (See Figure 3)

Key Features and Benefits ofTRICENTRICTriple Offset Butterfly

Valves:

Over 1500 valves installed at nuclearplants including containment isolationand 150 containment purge/ventapplications.

TRICENTRIC manufacturing always

maintained in the United States

All Approved Vendors located in NorthAmerica (U.S. & Canada)

Non Interference Seal = No Galling orSeat/Seal Wear.

Non-Jamming Seating = No Sticking.

No Resilient Seal = No Tearing, NoWash-Away, No Temp/Rad Effects.

Shaft Does Not Penetrate ThroughSeat/Seal = Less Susceptible to Leaks.

Seal is Assisted By Pressure = Better

Seating Under Higher Pressure.

Recently chosen by Westinghouse fortheir AP1000 Containment Isolation andPurge and Vent valve applications

Seal does not experience set like softseated designs.

Torque Seated with Metal-to-Metal Seal= No EQ concerns, Longer Life.

Torque seated not, position seated = Noneed to find sweet spot for seal.

S lf Adj ti S l Will N t Sti k D


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Reference ListTRICENTRICPurge & Vent Valves:

PSEG Hope CreekValves: 6, 24 & 26 150 TRICENTRICContact: Craig Johnson-Design Engineer

Phone: (856) 339-1859Email: [email protected]

Energy Northwest Columbia GeneratingStationValves: 24 & 30 150 TRICENTRICContact: Joe Stacks Appendix J Coord.

Phone: (509) 377-4324Email:

Entergy Northeast Pilgrim StationValves: 8 150 TRICENTRICContacts: David Peyvan AOV Program

EngineerPhone: (508) 830-7538Email: [email protected]

AEP DC CookValves: 14 & 24 150 TRICENTRICContacts: Danielle Satkoski-AOV Prog. Mgr Phone: (269) 465-5901 ext. 1456

Email: [email protected]

Product Updates:

Clow Engineered Products began a rigoroustesting program in the late 1970s which wascontinued by C&S Valve. In 2010, Weir Valves& Controls completed QME-1 testing of theTRICENTRICto meet stringent Westinghouse

AP1000 requirements. The TRICENTRICvalvehas been fully flow tested (under choked flowconditions simulating the accident closurescenario) and endured the complete Purge &Vent Valve Operability Qualification Analysis, asrequired by NRC Branch Technical Position,CSB 6-4 & Guidelines for Demonstration of

Partial Test List:

1972-Colorado State University

Determine Hydraulic Characteristics

1981-Vought Corp.Operational Test for Nuclear Purge Systems(Oyster Creek)

1982-Clow Job Number 80-9490-01.02 and 03Purge & Vent Operability Qualification Analysis,

NRC Branch Tech, CSB 6-4, Guidelines forDemonstration of Operability of Purge and VentValves(AEP/DC Cook)

1983-Colorado State UniversityHydraulic Test for Cavitation & Torque

1983-Clow Job Number 82-2739-01(N)Purge & Vent Operational Qualification Analysis

(Bechtel for Pilgrim NPP)

1994 Utah State UniversityFlow & Torque Tests (Duke Power)

2004-Alden LabsFlow Test of Qty (4) 10 BFV-Seat Leakage &Cv

2010-Wyle LabQME-1 Testing for Westinghouse AP-1000

(*Please consult factory for copies of any reports listed herein)

Over 30 years of testing and unsurpassedmetal-to-metal sealing capability is the mainreason that many nuclear plants changed to the

TRICENTRIC

valve for Purge & Ventapplications. Throughout the late 70s and early80s, plants like Pilgrim, Limerick, Hope Creek,Salem, Columbia and ANO continued to failLLRTs with the originally installed soft seatedbutterfly valves. The metal seals inTRICENTRIC valves do not degrade due to


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After the above mentioned plants changed toTRICENTRIC Triple-Offset Valves, many have

enjoyed extending LLRT testing requirementswithout experiencing failures. Also, severalplants withdrew from Containment AtmosphereOwners Groups due to the superb leak rate testresults experienced on a repeated basis.

In review, TRICENTRICTriple Offset Butterfly

Valves have several desirable operating

characteristics over conventional butterfly

designs, which make them better performers in

Containment Purge and Vent applications:

TRICENTRICValves use a non-elastomericseal to maintain tight seat leakagerequirements. This is a major advantageover butterfly valves with resilient seats, asthe elastomers tend to break down in the

high temperature and radiation environmentfound inside containment. This leads toincreased leakage on LLRT testing andrequires maintenance to replace the resilientseal. Resilient seals are not compatible withboric acid chemical spray used duringemergency shutdown containmentoperations which could result in seat

degradation resulting in potential seatleakage.

Age hardening is another potential problemwith resilient seals. These valves may sit inthe open or closed position for extendedperiods of time. The resilient seal, whichmaintains a seal by means of surfaceinterference, will conform to any area ofinterference. As the rubber age hardens, thesoft seat maintains the conformed shape.When the valve is stroked and subsequentseat leakage testing is performed, theresilient seal will often have an area that isunable to conform to the adjacent seating

Sonic velocity choked flow characteristicsassociated with a DBE may result in tearing

of a resilient seat during the final degrees ofvalve stroke. This would render the valveincapable of performing its intended safetyfunction of preventing effluent contaminationto the surrounding environment.

The TRICENTRICMetal-to-Metal torqueseated design is fully capable of meetingextremely low leakage values (even zero

leakage) under containment testingconditions. This has been proven in 3rdpartytesting, in our shop and in the field.TRICENTRICvalves have undergone50,000+ cycle stroke testing without any lossof performance in the sealing mechanism.

Figure 5 TRICENTRIC

with Pneumatic Actuator


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General Design Description Valve AssembliesAir Operated ValvesValve Tag Number TBD

Valve Overview:

12 Class 150 TRICENTRICValvesupplied in Carbon Steel (SA516 Gr. 70) construction.

Designed to ASME B16.34 2009 Edition and meeting Weirs Quality Assurance Manual Rev.6, dated23 June 2011 for ASME Sec III Div. 1, Class 1, 2 and 3. 10CFR50 Appx B and 10CFR21requirements apply

QME-1 Qualified Triple Offset metal seated butterfly valve

Dimensions, weight and Cv values per Weir TRICENTRICreference valve drawing.

Metal on metal seating, with non-jamming, non-interference seal.

Seismic mounting bracket and adapter for connection to Pneumatic Scotch Yoke actuator.

Actuator Overview:

Actuator: QME-1 Qualified Scotch Yoke Pneumatic Spring Return sized to operate with 100 psig airsupply with Fail Closed (FC) requirement

Closure requirement: 100 psig differential

Includes Manual override feature (Hydraulic, Gear w/ reach rod feature)

Accessory Overview:

Solenoid Valve Electrical component used to control the valve. Design includes Qty (2), One (1)being the primary and the latter being a back-up (for redundancy) and having Environmental/SeismicQualification for the intended service

Limit Switches Qty (2) Proximity Switches to indicate Full Open and Full Closed valve position,

having Environmental/Seismic Qualification for the intended service

Optional Teledyne Smart Stem (to support torque measurements for routine testing)


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Component Bare Stem Outline Drawings with Cross Sectional View

of Drawing with Bill of Materials

Figure 7


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Component Assembly Drawings with Sectional Viewof Drawing with Bill of Materials

Figure 8


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