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Existing steam piping - B31.1 clause for code compliance 2

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rbel038

Mechanical
Apr 12, 2011
19
Hi,

We are tieing into an existing steam header that has been in a plant for the last 20 years and has little to no information about it.

I seem to recall that there is a clause somewhere about pressure pipe or equipment that has operated safely in service as being code compliant. Perhaps it was B31.3 or even section VIII... The reason being we cant prove (due to lack of info) that the existing piping is compliant. There is a long hard road of NDE and design to get wallthicknesses through out the pipework if we cant prove it is compliant otherwise.

Im wondering if someone could shed some light on this , and the reference for the clause in the applicable code.

Regards,
Richard
 
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I have been in a few similar scenarios. In each one NDE was used to obtain wall thicknesses. The owner took responsibility of the material of the construction.
 
I seem to recall that there is a clause somewhere about pressure pipe or equipment that has operated safely in service as being code compliant.

No chance. This statement or similar to this is not in any ASME code or standard. For tying into existing equipment or components, you need an in-service repair code to follow rules for ensuring proper traceability of material for welding and using original code of construction requirements for NDT at the connection welds of old to new material. This is not that difficult, you just need to ensure the existing material is free of any service-related defects and the wall thickness is above minimum wall per ASME B31.1 Code.
 
Thanks for the replies. It seems someting like API 579 will be the way to go in regards to assessing the current pipe. Traceability of pipe material will be close to nil, I have some hand drawn isometrics that list API 5LB as the piping material but no documentation to confirm this is the fabricated pipe. Like you say Robin i think its a case for presenting this to the owner and getting them to take on some risk in regards to the existing materials of construction.

I havent had cladding/insul off piping this old before so im not sure whether any markings would still exist on the pipe runs.
 
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