IMPACT TEST REQUIREMENT (ENERGY & TEMP) ACCORDING TO B31.8 2

[peter vaf]

Dear Friends,

I am working on designing Gas pipeline (Flare line) with @-46 Min Design Temp..
I can not find any Impact Test requirement/Table((ENERGY & TEMP), like B31.3 or ASME Requirement.

My suggestion to the client is to changing Designing code FROM B31.8 to B31.3

 

[david339933]

B31.8 is not applicable for temps above 450F or below -20F. See 802.12

 

[LittleInch]

I agree.

B31.8 is for buried gas transmission lines in the main, not low pressure flare lines.

And certainly not at that temperature. B 31.3 is much more suitable

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

 

[akpipelineengr]

I would submit that B31.3 is absolutely the right answer for flare service, but the temperature is not the reason.

B31.8 is applicable and regularly used for lines with -50°F MDMT. The -20°F limitation in 802.12 was removed years ago. It now just points to Section 812, which requires a fracture control plan (generally just CVN testing of pipe materials and as part of weld procedure qualification) for design temps below -20°F. B31.4 has substantially similar low temp requirements.

 

[SJones]

The perils of quoting superseded standards '

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[1503-44]

Even then it was not exactly prohibited, as long as the materials were suitable for temperatures.

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

 

[peter vaf]

Dear akpipelineengr,

Thank you for your reply.
Another issue is Max Temp(343 C)!

As you see in the Attachment,the Max Temp.(343 c )is out of the B31.8 Acceptance range

 

[georgeverghese]

This is the first time I've heard anyone calling a flare line as a "gas pipeline".

 

[LittleInch]

I think we've established that B31.8 is not the most appropriate design code to use for this pipe.

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

 

[1503-44]

There are plenty of b31.8 "vent lines" connecting to a packaged "flare stack". Where's the Flange?

https://www.johnzinkhamworthy.com/products-applications/flares/

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