ASME B16.34 - Creep/life time

[Mike298]

Hi All,
Does anybody know how much creep life time that the ASME B16.34 pressure classes are calculated with? As a example the stress table values in the creep range for B31.1 is as I understand it for 100 000 hours life time. I checked the ASME B16.34 standard, but is is not mentioned.
Best regards
Michael

 

[hsbcn]

I've not seen the 100'000-hour creep-reference in the ASME code, and wonder how many manufacturers would be able to verify their product line against such a limit, which might take more than a decade to reach under normal operating circumstances. The only manufacturer I've seen use the 100'000h limit is Leser (Safety Release Valves).

My focus is on valve stockists in the us and uk who supply duplex and super duplex valves, and inconel and hastelloy valves, plus titanium, alloy 20 and 904L valves.

 

[bcd]

For dwetails on how the B16.34pressure-temperature ratings were determined, refer to non-mandatory appendix B of this standard. Although creep is a consideration, creep life-time is not a factor because pressure alone is not the only item to consider. For example, a tightly sealed gate valve. The wedging action of the gate can cause greater stresses in the body than internal pressure alone. So how much time will the gate valve be shut in its lifetime? That can vary from never to always, so how would you factor this body stress from the wedge into creep lifetime?

what your looking for does not exist in valves. Not practical to do.