Understanding B31.3 para 345.5.4.b 1

[Stallionbreed]

I’m interested in doing pneumatic testing on some B31.3 piping and below is the requirement for the test pressure:

“Section 345.5.4 Test Pressure. The test pressure shall be not less than 1.1 times the design pressure and shall not exceed the lesser of:
a) 1.33 times the design pressure
b) The pressure that would exceed 90% of the pressure described in para. 345.2.1(a)”

345.2.1.a) says:

“Reduced Test Pressure. If the test pressure would produce a circumferential or longitudinal stress (based on minimum pipe wall thickness) in excess of yield strength at test temperature or is greater than 1.5 times the component rating at test pressure, the test pressure may be reduced to the maximum pressure that will not exceed the lesser of the yield strength or 1.5 times a component rating at test temperature.”

I know how to calculate circumferential and longitudinal stress but not sure what the code means by “component rating at test temperature”. What does this mean?
And, does 345.5.4b mean 90% of whatever the reduced pressure in 345.2.1.a comes out to be?

 

[LittleInch]

Component rating is anything that isn't a pipe. So a flange, an elbow, a valve, an instrument, or anything that can see the test pressure.

Second question is yes.

If the limit is the pipe then it becomes 90% of yield stress.

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