Welding of ASTM A671 CB60 and CB70 material

[sandypiping]

The header pipe is A671 CB60 material; we need to weld reinforcement pad to this, however, due to non availability of CB60 material, contractor is proposing CB70 material. I dont see much issue as both CB60 and CB70 have the same P nos; however, not sure whether to indicate any specific thing apart from this.

 

This reference indicates CB60 is fabricated from A515 Grade 60, while CB70 is fabricated from A515 Grade 70.
Both are weldable and I would say you are safe in permitting this substitution, provided your welding procedure specifications cover the change in ASME IX group number.

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