This standard describes iron-body, brass-mounted, nonrising-stem (NRS) gate valves, including tapping gate valves, 3-in. (75-mm) NPS through 48-in. (1,200-mm) NPS, and outside screw and yoke (OS&Y) rising-stem gate valves, 3-in. (75-mm) NPS through 12-in. (300-mm) NPS, with either double-disc gates having parallel or inclined seats, or solid-wedge gates. 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 full open position. The 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 16-in. (400-mm) NPS and larger. Valves for operating pressures that fall outside these limits are beyond the scope of this standard and require special consideration in design and construction. The major revisions in this edition of AWWA C500 include the following: editiorial changes to conform to current AWWA form and content; the "Modification to Standard" and "Acceptance" sections have been edited; Grades A-E brass replaced with standard copper alloy UNS designation; and, metric equivalents added.