[MW:24750] Carbon steel welding

Gents,

We have a 24" pipe rolled from SA 516 Gr 70, 6 mm thick as the pressure inside is 1.2 kg/ cm2 at 423 degree C flue gases.

For support we are welding saddle (RF pad) of IS 2062 Gr A, 8 mm thick. Theoretically it is CS to CS welding. Question is does our CS to CS WPS PQR okay or we need to create one. 

Highly appreciate useful guidance.

Regards,

Vinod Bhatt.