gate valve API600 fire testing requirements 1

[joskings]

I'd like to receive opinions about the obligation of API 600 gate valves for being fire tested in accordance with API 607-2005. In which cases do you think this will be absolutely necessary.
Moreover, your interpretation when the valve is closed and exposed to a fire,on how the increased pressure,due to the retained liquid (i.e.flammable hydrocarbon) in the cap (bonnet) cavity, is relieved.
Thanks a lot for your help.

 

[BigInch]

All we can say here is, if the valve is to be exposed to fire and you want some assurance that it will survive, use the spec.

Most of these valves have an internal one-way check valve opening to a passage from the bonnet back to the inside flow area of the valve. When pressure from fire increases pressure in the bonnet to a pressure higher than the pipe pressure, the check opens relieving bonnet pressure.

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