scope:

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. The manufacturer should be consulted for special conditions. Check-valve sizes described in this standard are 2, 2½, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 24, 30, 36, 42, and 48-in. (50, 65, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 750, 900, 1,050, and 1,200 mm) NPS. Sizes refer to the nominal diameter of the waterway through the inlet and outlet connections and the seat. 

Seating types. Check valves may be of the metal-to-metal, resilientto- metal, or resilient-to-coated seat construction as illustrated in Figure 1. 

Hinge arm types. Check valves may incorporate either a metal or resilient-hinge arm as illustrated in Figure 1. 

Waterway types. Swing-check valves may be of the clear waterway design (where the disc in the full open position swings clear of the waterway) or the full waterway design (where the disc in the full open position is not clear of the waterway, but the body is enlarged to provide full waterway area around the disc).

Pressure ratings. The working water pressure shall be a minimum of 200 psig (1,370 kPa) for check valves with diameters of 2-in. through 12-in. (50-mm through 300-mm) NPS inclusive. The working water pressure shall be a minimum of 150 psig (1,030 kPa) for check valves 14-in. through 48-in. (350-mm through 1,200-mm) NPS inclusive. The working water temperature shall not exceed 125°F (52°C). 

Conditions not described. The following design and installation conditions are not described in this standard.

Chemical. Swing-check valves for use in lines conveying water of unusual corrosivity are not described in this standard where the media being conveyed have a pH less than 6.

Hydraulic. Conditions of water hammer, hydraulic pulsation, and excessive operating noise are beyond the scope of this standard and require special design and construction consideration.

Purpose

The purpose of this standard is to provide the minimum requirements for swing-check valves for waterworks service, 2-in. through 48-in. (50-mm through 1,200-mm) NPS, including materials and testing.

Application

This standard can be referenced in specifications for swing-check valves for waterworks service, where the stipulations of this standard apply when this document has been referenced and then only to swing-check valves for waterworks service, 2-in. through 48-in. (50-mm through 1,200-mm) NPS.