This standard describes iron-body, brass-mounted, nonrising-stem (NRS) gate valves, including tapping gate valves, 3-in. (75-ram) NPS through 48-in.
(1,200-mm) NPS, and outside screw and yoke (OS&Y) rising-stem gate valves, 3-in. (75-ram) NPS through 24-in. (600-ram) NPS, with either double-disc gates having parallel or inclined seats, or solid-wedge gates. These valves are suitable for use in approximately level settings in water systems. These valves are intended for applications where fluid velocities do not exceed 16 ft/sec (4.9 m/sec) when the valve is in the fully open position.
1.1.1 Valve pressure ratings. The minimum design working water pressure shall be 200 psig (1,380 kPa) for valves 12-in. (300-mm) NPS and smaller, and 150 psig (1,050 kPa) for valves with diameters of 14-in. (350-mm) NPS and larger.
1.1.2 Conditions and materials not described. This standard is not intended to describe special conditions of gate-valve installation or operation such as built-in power drive, installation in unusually corrosive soil, conveyance of unusually corrosive water, excessive water hammer, or operation in a throttled position. Such
conditions are beyond the intended scope of this standard and require special consideration in design and construction. Joint accessories for end connections, such as bolts, gaskets, glands, follower rings, and so forth, are not described in this standard.