scope:

This standard is intended to cover API ringjoint dimensions for American Standard (ASA)¹ steel flanges, (threaded with API standard line pipe threads² 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 ring-joint flanges, or where ring joints are required in piping connections.

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

¹ASA Stondards mentioned herein may be Bocurcd from the Amorinan Standards Association, 29 West 89th St-, New York, N. Y.

²See API Stds. No. 5-F: Threads in Fittingi.