ASTM material welded to ASME material

Non pressure parts need not conform to a specification permitted by Sec VIII Div. 1. See UG-4 (b). The material must be of weldable quality....which A-36 certainly is (P1G1 as listed in Sec IX). No special requirements for PQR as long as impacts are not applicable.

PWHT follows construction code (Sec. VIII Div. 1) not material, regardless of what the material is usually used for.

Some of ASTM materials can be even used as pressure parts. Please refer to MANDATORY APPENDIX II especially Table II-200-1 (Eddition 2013 and newer. Earlier it was in introduction).

In additon to provisions in david339933 reply, the external attachment that will affect the structural integrity of the vessel (like supports) has to assure the toughness requirement at the operating conditions of the vessel. You may refer to UCS 66 (a) of Div.1 or 3.11.1.1 of Div. 2.

You need to give attention to materials that falls under A/SA-6 (like A/SA-36 & A/SA-283) since those materials falls under Curve-A. And, if you are not exempted by other paragraphs or your client doesn't allow to use those exemptions, then most likely you wil face a problem in the MDMT.

Regards,
M.Salaheldin
Static Equipment Mechanical Design Engineer

If shell material is HIC (Hydrogen induced cracking), internal parts welded to shell should be same quality of shell.

Regards
r6155

@r6155 but this is not code requirement. I believe that the original question is mainly for the code requirement. If we include the service requirements, then many other points will start to take place. For example the dissimilar weld on surfaces exposed to Wet Sour will be a restriction.

Regards,
M.Salaheldin
Static Equipment Mechanical Design Engineer