Valve working pressure and tempreture

[Cyrus444]

what is difference between working pressure and max pressure in asme b16.34?
Do I need consider the MAX pressure in pipeline which could happen once per year to select valve rate and class?

 

[LittleInch]

I don't understand your question.

ASME B 16.34 gives you maximum allowable working pressures. There isn't anywhere I can see that gives anything different, hence my confusion.

Pipeline design codes generally (except ASME B 31.8) give you an allowance of 10% over the design pressure for surge / incidental or occasional over pressure events. This includes all fittings and flanges associated with the pipeline.

But you need to give us numbers here.

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Also: If you get a response it's polite to respond to it.

 

[shvet]

Do I need consider the MAX pressure in pipeline which could happen once per year to select valve rate and class?

What is the piping design code?

(f) Occasional variations above design conditions shall remain within one of the following limits for pressure design.
(1) Subject to the owner’s approval, it is permissible to exceed the pressure rating or the allowable stress for pressure design at the temperature of the increased condition by not more than
(-a) 33% for no more than 10 h at any one time and no more than 100 h/y, or
(-b) 20% for no more than 50 h at any one time and no more than 500 h/y
...
(2) When the variation is self-limiting (e.g., due to a pressure-relieving event), and lasts no more than 50 h at any one time and not more than 500 h/y, it is permissible to exceed the pressure rating or the allowable stress for pressure design at the temperature of the increased condition by not more than 20%.

 

[LittleInch]

Just note than B 31.3 is not a pipeline code, but piping. They work slightly differently.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.