API 1104 code interpretation for base metal

[sgcwi]

I need to qualify a welding procedure to API 1104, welding X60 pipe to Gr. 4130 material. I would like to know if I can do this using a pipe coupon that is "dual certified X60/X65", or would that pipe only be usable to qualify an X65 procedure?

[arcpro]

I would recommend that you do not use dual certified pipe coupon for qualification of X60 piping.

[arcpro]

Technically speaking, a dual certified X60/X65 would be no different than a X60 certified piping and so would not be having any different mechanical properties. On these technical grounds, you can use a dual certified X60/X65 pipe coupon for welding qualification of X60.

On the other hand, a dual certified pipe belong to two different materials group as per API 1104 should not be purchased, as you know that X60 and X65 belongs to two different material groups (see para 5.4.2.2). This can be a point picked up by an inspector or site auditor while auditing welding jobs.

That's why I recommend that a pipe certified in two different material groups as per API 1104 shall not be used as a coupon for welding qualification.

I hope you understand my point.

[sgcwi]

Thanks. I understand the point, and it does make sense.

[mechcolor]

4130 has higher strength than X60 pipe, I believe it's above 60 ksi (other than annealed form). As per API 1104, welding qualification would be made based on the pipe having higher strength.
I hope you would consider that.