Welding with P22

By Yasir Mazhar Date 01-06-2009 14:47

I am working as a mechanical Engineer in a 1300 MW thermal power plant. currently working on a project of replacing around a mile length of mostly high pressure instrument piping.
Since piping is 1/2" nominal i am opting for a SMAW socket weld joints. it seems ok for most, but can anyone recommend A335P22 compatible filler materials and welding procedures?
i am also looking at some mixed joints incorporating A53GrB-SS304, A106GrB-SS304, A335P22-SS304.
Can anyone please help me out?

Thanks

By Shane Feder (****)

Date 01-06-2009 20:22

Yasir,
I would strongly recommend GTAW over SMAW for 1/2" socket welds.
The control and skill level required to weld SMAW on that size of pipe and still produce acceptable welds is very high.
Do you not have qualified WPSs that should tell you the answers to your questions ?
Why is a mechanical engineer responsible for welding ?
I would also strongly recommend you get a Welding Engineer or CWI involved or you might end up with major problems.

A335 P22 - A335 P22 GTAW (ER 90S-B3) SMAW (E9018-B3)
A53 Gr B - SS 304 GTAW (ER 309L) SMAW (E309L)
A106 Gr B - SS 304 GTAW (ER 309L) SMAW (E309L)
A335 P22 - SS 304 GTAW (ER NiCr-3)
Regards,
Shane

By Yasir Mazhar Date 01-07-2009 07:25

Thanks Shane.
We do not have a certified welding inspector on our station as yet. Concerning the particular piping, ZELIN, the company responsible for erection did not submit WPS for the job. in the past, most jobs have been done simply on speculation. I am currently trying to formulate some procedures and get some training as well.
Thanks for your help.
Yasir

By slagline 3 (**)

Date 01-07-2009 15:31

I PM'd you.