scope:

Description

This type of device is located in the domestic water distribution system and is designed to supply potable water to a drain trap to maintain the water seal. A means for the prevention of back-siphonage shall be incorporated as part of the device and shall comply with backflow siphonage testing in Section 3.4.

Size

Water distribution line connections shall be not less than 1/2 NPT pipe size. Trap seal makeup (discharge branch) connections shall be minimum 1/2 NPT pipe size.

Flow

The rate of water flow to the trap shall be fixed or adjustable. If the water flow to the trap is adjustable and the means of adjustment is located downstream of the back-siphonage backflow device, the means of adjustment shall not be capable of shutting off the flow of water. The device shall provide intermittent discharge to the trap in response to the flow or pressure changes in the supply line.

Pressure Requirements

Device shall be designed to withstand a minimum hydrostatic working pressure of 862.5 kPa (125 psi).

Operating Range

Devices shall be designed for minimum operating range of 138-552 kPa (20-80 psi).

Sliding Parts

Parts shall prevent galling and sticking when tested to Section 3.2, Cycle Test.