scope:

This standard covers over-all dimensions, toler-ances, ratings, testing, and marking for wrought carbon- and alloy-steel factroy-made buttwelding fittings of NPS ¹/₂ throguh 48.

Fittings may be made to special dimensions, size, shape, tolerances, or of wrought materials other than those covered by this standard by agreement between the manufacturer and the purchaser. When such fittings meet all other stipulations of this standard, they shall be considered as being in partial compliance therewith, provided they are appropriately marked.

Fabricated laterals, or other fittings employing intersection welds, shall be considered as pipe fabrication, and as such should be designed in accordance with the requirements established in the American National Standard Code for Pressure Piping (ANSI B3 1).

This standard does not cover low pressure corrosion resistant buttwelding fittings. See MSS SP-43, Wrought Stainless Steel Butt-welding Fittings.