Choice of material to join T-22 to Carbon steel pipe

[rmillercwi]

I am working on a procedure to repair a branch connection of an extruded nozzle connection off a manifold to a feeder pipe.

Header pipe A53 B. Feeder connections were once SA209-T1a and have at some point been switched out to T22. The failure is some distance away from the header into the tube. The plan is to simply remove the tube some distance beyond the failure and replace it presumably with another round of T22. Failure mechanism is something with restaint in the design.

This makes the connection a P1 to P5A connection. Nothing special about it.

Two questions:

1 - The existing tube connection from the header is an extruded type not unlike a circumferential weld @ the actual weld. Can I call this a circumferential weld? By doing so I can exempt PWHT as these connections are under 5/8" thk.

2 - Assuming the stress values of the material checks out, would it be wise to use T-11 here ( for the pup piece) in lieu of T-22? This would make the tube to header connection a P1 to P4 connection and the tube to tube weld a P4-P5A. I have seen others design transition pieces (CS to P4 to P5a) in lieu of jumping right from CS to P5A and presumed it was someone trying to gradually transition from CS to P5A. Maybe doesnt make any difference. Or does it?

 

[DekDee]

These are questions that should be addressed by a Welding Engineer - not an internet forum.

 

[rmillercwi]

Thanks dekdee. It would seem that consulting with a weld engineer in 95% of these threads would have merit. I discuss every move I make with a weld engineer. I just like to be somewhat informed ahead of time.

 

[DekDee]

Sorry if my post came across as a bit harsh.
All the best with your endeavours,
Cheers,
Shane

 

[Dhurjati Sen]

Dear rmillercwi,

1. It is a stub-in. Consider it as a butt weld. So answer is NO.

2. A few decades back these transitions had merit. Now with much advanced welding equipment and filler, you can weld CS with P5A.

Regards.

DHURJATI SEN
Kolkata, India

 

[weldstan]

Multiple filler metals have been used to make this joint from carbon steel to matching chemistry of the higher low alloy steel. ER70S-2 or ER70S-6 or ER90S-B3 or an intermediate filler like ER80S-B2 have all been used to weld this joint.