Knowledgebase Article 1073

Question:

Can different materials be specified for a flange and its attached blind flange?

Answer:

A blind flange (bolted cover) attached to a flange designed per Section VIII Division 1, Appendix 2, may be designed with a material that is different from that of the mating flange.

A standard ASME/ANSI B16.5/B16.47 blind flange must be the same material as the mating flange.