Requirement for PWHT

[fakhmed]

Dear All,

Does the API1104 or the API 5L requires a post weld heat treatment after welding API 5L X70 pipes ?

If no, technically is it necessary to PWHT a pipe API 5L X70 having 18mm thickness?

Thank you

 

[FIF99]

Hi

It strongly depends on the design code, and the minimum design temperature. According ASME B31.3 the common rule is PWHT above 19mm for carbon steels.
For X70 there may be other requirements, since it is a special high strength grade. I don't know if this material is listed in the ASME B31.3 in the first place.

Which design code apply for the X70 materials?

Regards,
FKE

 

[fakhmed]

Thank you

The design standard is API5L (Pipe line)

You know API5L has not the same approach as ASME codes

The API5L require PWHT for high frequency electric welding process. But for the others refer to the manufacturer decision. Now it is very important to get other reference or sientific book as a guide for PWHT identification

Best regards

 

[SJones]

Is this referring to the seam weld of SAW pipe? If yes, the need for PWHT will be driven by the specific application of the pipe (end user specified)and the need to meet any supplementary requirements that are imposed (hardness for example).

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/