scope:

This standard covers flanged cast-iron gate valves in sizes NPS 2 through 24 correspnoding th nominal pipe sozes in ANSI B36.10.

This standard covers valves in pressure Claases 125 and 250 in ANSI B16.1

The valve is the outside screw-and-yoke (OS&Y) type with rising stem, nonrising stem, nonrising lahdwhell, bolted bonnet and various types of gates.

Classes 125 and 250 cast-iron valves made in accordance with this specification shall conform to Classes 150 and 300 steel valves made to the requirements of API Standard 600, except as modified herein.

The standard nomenclature for valve parts is shown in Figure 1, which also illustrates an acceptable valve design.