Use of B31.4 for temperatures belwo -30 degrees
Use of B31.4 for temperatures belwo -30 degrees
(OP)
I was recently made aware that the B31.4 code states (400.1.2) that it was not developed for piping with design temp. less than -30 dgrees C. My query is what code do we follow for cases where we have lower temps e.g. -34 C as is the case for some areas of NE USA.
The Canadian pipeline code Z662 which is similar to B31.4 does not have this limitation.
My interpretation is although it says "not developed", we can still apply the code with engineering judgement .
Am I correct ?
The Canadian pipeline code Z662 which is similar to B31.4 does not have this limitation.
My interpretation is although it says "not developed", we can still apply the code with engineering judgement .
Am I correct ?





RE: Use of B31.4 for temperatures belwo -30 degrees
It is less hassle to use a low temp material like A333 instead of A106 grade B.
http://cstools.asme.org/csconnect/pdf/CommitteeFil...
RE: Use of B31.4 for temperatures belwo -30 degrees
Use A333 as bimr suggests.
I have done the same for liquid anhydrous ammonia pipeline at -33C using A333.
RE: Use of B31.4 for temperatures belwo -30 degrees
RE: Use of B31.4 for temperatures belwo -30 degrees
RE: Use of B31.4 for temperatures belwo -30 degrees
RE: Use of B31.4 for temperatures belwo -30 degrees
Also B 31.4 has another section - 401.2.3.7 which strongly implies that outside the -30C / 120C range the design stress or design factor would need to be modified. Sure you can get material to work down to temperatures outside those limits, but maybe not at a DF of 0.72??
31.3 would result in a higher wall thickness, but work outside the written boundaries of a code and you are in gradually increasing murky waters.
The real issue is is that a temperature the pipe will actually see.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Use of B31.4 for temperatures belwo -30 degrees