Welding X65 to X42 as per API 1104

[zirsald]

Dear members,
Could you please let me know if I can weld API 5L X65 pipe to API 5L X42 pipe using a PQR that has been performed with API 5L X70 pipe
Thanks

[mohd]

dear,

As per API 1104, par. 5.4.2.2 c- Not allowed.
For base metals with a specified minimum yield strength greater than or equal to 65 ksi, each grade shall receive a separate qualification.
So the API 5L X65 to API 5L X42 welding using procedure that qualified with API 5L X70 isn't possible.

Please share filler metal's or electrode's details used to qualify X70 welding procedure and check suitability for X65 to X42 welding.

Regards,
mohd.

[mawsamit]

I agree with Mohd, you cannot use a X70 procedure in order to weld X65 to X42. In addition, please note that if you qualify procedure by welding X65 to X42 then you qualify for welding only X65 to X42. So, I suggest you qualify procedure by welding X65 to X65 with which you qualify not only for welding X65 to X65 but also for welding X65 to lower grades (X65 to X60, X65 to X56, etc), provided that all other essential variables apply, since in par. 5.4.2.2 specified that "when welding materials of two separate material groups, the procedure for the higher strength group shall be used".

[victorsteel]

u cant use API 5L X65 pipe to API 5L X42 pipe bec each grade have separate specification for more detail check http://www.api5lx60.com/