7 replies to this topic

[shin29]

Dear all
Happy rains to all

Sirs,
in my plant we have a carbon steel pipe line header of flange rating 600 psi. Its rated pressre is 102 barg.

Can we operate this pipe line on 100 barg? if NO, than which standdard and clause retricts us?

And if YES, than:

1 . what do standards allow us?
2. what are the factors we should be aware of before doing this - such as a pressure shock?
3. at what set point should a PSV be set?

Regards,
Shin

[fallah]

Shin,

At first specify the piping code which the mentioned pipeline has been designed based on.

Fallah

[shin29]

Fallah,
Sir, pipeline has been designed based on ASME B16.5 . thanks in advance for your reply.

Regards,
sahil

[fallah]

Shin,

ASME B16.5 is the standard for "pipe flanges and flanged fittings" not for pipeline design. You should specify the ASME code for pressure piping, e.g. ASME B31.8 is to be used for "Gas transmission and distribution piping systems".

Fallah

[jrtailor09]

Shin29,

Piping design pressure changes with temperature.

Check your PMS (piping material specification) @ 100 barg pressure what is maximum allowable temperature ?

Check your relieving fluid properties ( temp. pressure etc) fall under this limit ? If yes then you can use this piping.

Regards,

[shin29]

Dear Mr. Fallah
Pipe design code is ASME B36.10M
Thanks for correcting me
regards,

[fallah]

shin,

This Standard (ASME B36.10M) provides dimensions of welded and seamless wrought steel pipe for high or low temperatures and pressures applications. It isn't a pipeline design code.

Fallah

[TS1979]

Shin,
with the y
1. You need to check your company specification with the piping class.
2. As Justin said, maximum allowble working pressure is related to corresponding operating temperature.
3, Sometimes, you cannot just look at the line destination table (LDT) because the creater of the LDT might write an improper design pressure.
4. Based on the piping class, you can decide if you need to rerate the piping design pressure and rehydrotect the piping with a higher/lower testing pressure.
5. The PSV set pressure should be no more than the maximum allowable working pressure. Of course, the set pressure can be lower than the maximum working pressure.
6. The operating pressure shouldn't be over 93% PSV setting pressure. Otherwise, you will experience PSV leaking.