Fire Safe test for Butterfly valves

[AM14]

Dear Members

Please advise whether fire test can be done on Butterfly valve as per API 607 - Double offset, Double Flanged 12" 150# RF, Body-A216 WCB,Seat : Stellite #6,Disc-WCB + EPDM;Stem- SS316; Operator - Gear
The supplier says Butterfly valves with EPDM seats on disc don't require a fire-safe test certificate. Is that true.?. Can i say the same to End user?

 

[johnengkol]

Agree with your supplier, EPDM Seat are elastomer, will be damaged when performed fire test

 

[Danlap]

Hi,

I see that this post is redundant and might confuse someone.
I’ve provided answer on similar post. If end user requires fire test, then manufacturer shall comply with it.
API 607 with title 'Fire test for Quarter Turn valves and Valves equipped with Nonmetallic seats' specifically made to address End user requirement. This include elastomeric seat.

Yes, almost all soft materials will be damaged during fire test (exposed to 750++ degC), but the question is how much the leakage would be. And fire test is only for prototype testing, hence already ‘burned’ valve cannot be used for installation. Unless it is repaired as new again.

Fire safe test in a nutshell is for End User (mainly oil and gas?? This I am not sure) to determine process safety risk whether in the event of pool of fire, that such (leaking) product will contribute more to fuel the fire.

External leakage à there should be no external leakage within 30 minutes. I believe this is maximum agreed time for first response to be completed such as required amount time for firefighter to arrive, Offshore personnel to abandon platform/ already in the life raft, etc. hence API 607 stated duration of testing 30 minutes.

Internal leakage (through seat) à maximum allowable product leak rate passing through ‘burned’ seat. Since it may feed more ‘fuel’ to downstream locations, before fail protocol manage to isolate the product.

All of data above (external/internal leakage during and after burning; duration) are required by Process safety department for risk assessment and cascade that into requirements such as but not limited to:

• Closing/opening time of SDV and BDV
• Emergency protocol for evacuation
• Fail to close/open actuated valves requirements
• Etc.

Sometimes this risk assessment must be reported to local municipalities’ safety authority.

Valves not subject for fire test:

• Valves with PTFE and elastomeric gasket on gland and or body to body/bonnet such as some soft seat ball valves, needle valve with PTFE packing and lined butterfly valve. Why? Most likely it will be burned and contribute to external leakage before 30 minutes passes
• If Plants or end user already declare that risk of pool of fire is ALARP e.g. water treatment plant, certain chemicals plants, dairy products, etc. Do realize that some of common supplier for these industries might not be familiar to fire-safe requirements.

Allow me to rephrase main question of this topic:

Can an EPDM seat butterfly valve meet leakage requirement as per API 607 and whether it is mandatory or not (for fire safe)? Yes a good design butterfly valve will still be able to manage seat test leakage rate (Table 1 - API 607) even with already burned seat(s). And as per API 609 if purchaser specifies it then it’s a must.
under the assumption that valve selected has graphite packing/gaskets either as primary or secondary.

Hope that helps.
Kind regards,
D