Metal-Seated Gate Valves for Water Supply Service

Abstract

This standard describes iron-body, metal-to-metal seated, nonrisingstem (NRS) gate valves, including tapping gate valves, 3 in. (75 mm) through 72 in. (1,800 mm), and outside screw and yoke (OS&Y) rising-stem gate valves, 3 in. (75 mm) through 72 in. (1,650 mm), with either double-disc gates having parallel or inclined seats, or solid-wedge gates.

These valves are suitable for use in approximately level settings within 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.

Valve pressure ratings.

The minimum design working water pressure shall be 200 psig (1,379 kPa) for valves 12 in. (300 mm) and smaller, and 150 psig (1,034 kPa) for valves with diameters of 14 in. (350 mm) and larger.

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.

Purpose

The purpose of this standard is to provide purchasers, manufacturers, and suppliers with the minimum requirements for metal-seated gate valves for water supply service, including materials, design, testing, inspection, rejection, marking, and shipping.