scope:

This standard is intended to cover A. P. I ring joint dimensions for American Standard (A S A )* steel flanges, (threaded with A. P. I standard line pipe threads! or American Standard thread), other sizes of flanges as required, and rolled, and slip-on welding and welding neck flanges These ring-joint dimensions are also to be used on steel flanged valves and fittings where connected to ling-joint flanges, or where ring joints are required in piping connections.

This standard also covers ring-joint flange unions for use with A. P. I. tubular goods↑, (line pipe, casing, drill pipe, and tubing).

*A S A Standards mentioned herein may be secured from the American Stanards Association, 29 West 39th St, NewYork N Y

↑ See A P I Stds No -F Threads in Fittings