a. This standard covers steel gate valves with flanged or buttwelding ends@ in nominal sizes of 1 to 24 in. corresponding to nominal pipe sizes (NPS) in USAS B36.10. b. This standard covers valves in nominal pressure ratings of 150 to 2500 lb as in USAS B16.5. c. The valve is the outside screw-and-yoke (OSY) type@ with rising stem@ nonrising handwheel@ bolted bonnet@ and with various types of gates. d. The standard nomenclature for valve parts is shown in Fig. 1@ which is also illustrative of some acceptable gate valve designs.