Root weld repair directly from the inside

[Pipoy04]

I want know if there is any prohibition against making a repair on header to nozzle weld (8" dia. header x 6" dia. nozzle) to the root side of a butt weld that was made from one side when a flaw, such as incomplete penetration, is discovered? Can anyone give a supporting documents base on code? Our client request us to do repair from the outside. Thank you.

 

[DekDee]

Pipoy,
Pretty sure you will find nothing prohibiting it in any codes but generally you have to have a qualified repair procedure for it.
Small repairs (internal touch ups) can sometimes cause the most metallurgical problems if dealing with certain materials.
Regards,
DD

 

[racookpe1978]

If access permits.
If SAFE access permits. (FME (exclusion of the welding grit and debris from the clean areas upstream and downstream of the repair, ventilation for the welder, harness and retrieval (or other method in the confined space), continuous monitoring of the air supply, room to operate and weld and grind and inspect ....)

May need scaffolding or support - or might be able to just climb in the PV.

All that being accomplished, it is a dangerous place. Preheat/PWHT, interpass temperatures may be fatally too hot for work.

 

[metengr]

There is nothing technically to prevent this type of weld repair - it is a process detail that does not enter code or standards activities.

 

[weldstan]

There is nothing to prohibit repair from the ID in ASME B&PV and Piping codes. One assumes that your branch connection is a set on o'let type and the root is accessible. If hardness must be controlled to prevent in service stress corrosion cracking, you should qualify a procedure, mimicking the repair, with hardness testing.

 

[DekDee]

"If access permits.
If SAFE access permits. (FME (exclusion of the welding grit and debris from the clean areas upstream and downstream of the repair, ventilation for the welder, harness and retrieval (or other method in the confined space), continuous monitoring of the air supply, room to operate and weld and grind and inspect ....)"

racookpe1978,
If a welder got shoved up an 8" dia. header I think ventilation would be the least of his worries !

 

[racookpe1978]

Depends how far up the 8 inch the repair is. 8<)

Might need a little bitty DotCo grinder and burr bit though.