This standard describes only iron-body unassisted swing-check valves, 2-in. through 48-in. (50-mm through 1,200-mm) NPS, with mechanical-joint or flanged ends that are installed in approximately level settings in water systems.

This standard describes the double check-valve backflow prevention assembly for potable water applications. The assembly shall be capable of withstanding a working water pressure of at least 150 psi (1,034 kPa) without damage to working parts or impairment of function and for operation on hot or cold potable water lines.

This standard describes the reduced-pressure principle backflow prevention assembly for potable water applications. The assembly shall be capable of withstanding a working water pressure of at least 150 psi (1,034 kPa) without damage to working parts or impairment of function and for operation on hot- or cold-water lines.

This standard describes 1/2-in. (13mm) through 6-in. (150mm) air-release valves and 1/2-in. (13-mm) through 20-in. (500-mm) air/vacuum and combination air valves having gray cast-iron or ductile-iron bodies and covers.

The purpose of this standard is to provide minimum requirements for stainless steel and ductile-iron body knife gate valves with resilient and metal seats, including tapping knife gate valves, for use in water, wastewater, and reclaimed water systems, including materials, design, testing, rejection, marking, and shipping.

This standard decribes the special protective interior coatings for valves and hydrants used for water supply service.