Weld repair of a sour service carbon steel vessel

[metalhoosier]

I have a vessel 14psig and 220F that needs repair due to a pinhole leak. The vessel contains sour service gas. The vessel is 40+ years old SA-212 material, 0.250 min wall thickness that was fully stress relieved after fabrication. We intend on:
1) performing a local hydrogen bake at 600F for 2 hrs
2) pre-heat to 200F and weld repair
3) PWHT local area at 1100F for 15 minutes

The intent is to follow the API 939-B specification. Is this overkill? Any comments would be appreciated.

 

[vesselfab]

nope...not at all.

good plan

 

[metengr]

One added item - wet fluorescent MT of the repair region after completion of welding. You need to verify the integrtiy of the repair.

 

[metalhoosier]

Vesselfab and Metengr,

Thank you for your comments on this issue. I deal regularly with pressure vessel repair (I guess that's a good thing) but I don't have much experience with the sour gas service and hydrogen entrapment, so this seemed a little overkill, but it's good to know it is not.

Thank you,
MetalHoo