Compressed air line weld joint

[billMcL]

Part of the assembly we manufacture has a large volume air compressor. There is steel piping coming off of an air storage tank (an ASME "U" stamped vessel with a MAWP of 150 psi.) The safety relief valve is also 150 psi. The steel piping is carbon steel 4" dia. sched. 40. The welded joints are detailed as partial penetration. Looking into the ID of the elbows it is easy to see the groove of the root -lack of penetration. For this application, what would the aplicable code of manufacturing be (ANSI B31.1?) Is this type of weld joint acceptable in this application? Thanks!

 

[metengr]

Partial penetration?? I would recommend ASME B31.1 or B31.3 Piping Code for starters. Get rid of these weld joints immediately, and make them full penetration butt welds. In the meantime, keep away from these partial penetration welds in service until you change them out.

 

[MJCronin]

bill..

A compressed air system operating at the pressure you describe must be built to rules contained within the ASME B31.1 piping code. This design code requirement is enforced as law in any US states.

B31.1 specifically bans parial penetration welds for the fittings you describe.

This is not a matter of "engineering judgement"

- MJC