Material Selection as per Table H-1 / H-2 of API 610 10th Edition.

Dear Members,

I have come across the following probelm while reviewing Pump Vendor dwgs. and Part List/Material.

- Requirements of Material as per Data sheet = Material Class A-8 (As per Table H-1).

- For Casing Bolts/Nuts, Vendor has mentioned A193 Gr B7 / A 194 Gr 2H (As per Table H-2)while, My comment is that, the Casing Nuts / bolts must be A 193 Gr B 8 M / A 194 Gr B 8 M (Also, as per Table H-2 for Austenitic SS Material Class).

- Vendor clarify that, as per A-8 Class (Table H-1), Material of Case/Gland Studs required AISI 4140, So, Refer Table H-2 for AISI 4140 (That is A193 Gr B7 / A 194 Gr 2H ).

- While, my argument is that, the Material Class A-8 (As per Table H-1) is for Austenitic Stainless Steel, so, we have to refer Table H-2 for Austenitic SS and accordingly, the Case/Glans Stud must be A 193 Gr B 8 M / A 194 Gr B 8 M.

I support my argument also, because Casing is in Austenitic SS so, the Bolts should also be in SS and not CS.

Can any one clarify How to read Table H1 / H2 OF API 610 10th Edition.

Also, my interpretation is correct or not ?

With regards,

Nilesh.