Gas terminal piping integrity assessment

[nesamani1983]

Hi all, I am working in Gas pipeline transportation, has cross country pipelines and terminals.

I have below doubts
1) Is there any way to find the terminal pipe grade? any survey . Because in old terminals, pipe/bend materials used are of different thickness than the A333 or A106 Gr B. Also the documents are not available.

2) Kindly send me the sample calculation for Minimum required thickness as per ASME B 31.3

3) If the terminal piping, "measured thickness" is less than the "Minimum required thickness as per ASME B 31.3", what action to be done?
If the terminal is operating less than the Design pressure, can we do any Engg assessment and accept the metal loss?

 

[1503-44]

Ultrasonic inspection will show thickness and condition of pipe wall.

See the code for the thickness formula.

If you do not have sufficient wall thickness, you must reduce the max operating pressure.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

1) Send a sample off for nechanical testing and maybe chemical analysis will give you dome ideas or data to use, especially yield strength and UTS.

2) Use the calc in the code. To get S use the lowest you can find until you know. Maybe A25?

3) Replace it or lower the design pressure...


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

 

[pmover]

to supplement previous posts, be sure of the appropriate pipe code. for gas pipeline transmission, B31.8 is the appropriate code.

 

[1503-44]

If the piping is downstream of a client's meter, B31.8 coverage generally ends.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[brimmer]

1) yes you can do two things, provide a cut out section of material and send to the lab for standard testing (which is often difficult to obtain given it is in service) this is the best option, option two is there are portable testers that have come onto the market in the last year thanks to the PHMSA Gas Megarule so you don't have to remove a coupon, can do while line is in service... companies like Acuren and PLX have testing machines that can do this, though not geared to A333 pipe.

2) as per code assuming you can get the grade from testing, if not assume worst case

3) Replace (or reduce pressure based on t min)