ANSI B16.5 flat flanges with ANSI B16.1 flat face flanges. 1

[ligin18]

Dear flange experts.

I´d like to know if it´s possible to mate ANSI B16.5 flat flanges with ANSI B16.1 flat face flanges.

I have carbon steel pipes with ANSI B16.5 A105, class 150 flat face flanges, and want to install betwen them cast iron valves with ANSI B16.1 flat face flanges

 

[JohnGP]

It's actually ASME B16.5 and B16.1, to put my pedantic hat on, but yes you can mate ASME B16.5 Class 150 flanges to ASME B16.1 flanges. Having flat face flanges is a good (essential) start, but see also Clause 5.3.5 in ASME B16.5 for recommendations for bolting to cast iron flanges.