scope:

Description

The devices covered by this standard are those which have functional capabilities for preventing both backsiphonage and backpressure and which can operate under continuous or intermittent pressure conditions. These devices have 2 independently operating check valves separated by an intermediate chamber with a means for automatically venting it to the atmosphere and can be installed in the horizontal, vertical up or vertical down orientations. The check valves are force loaded to a normally closed position and the venting means is force loaded to a normally open position.

Size Range

Inlet and outlet pipe sizes are 1/4 to 3/4 NPS (8 mm to 20 mm) inclusive.

Minimum Pressure Rating

The device shall be designed and constructed for a working pressure of at least 150.0 psi (1034.2 kPa) static.

Temperature Range

The device shall be designed and constructed for normal flow temperatures of 40.0°F to 210.0°F (4.4°C to 98.9°C) and an emergency backpressure temperature of 250.0°F (121.1°C).

Flow Rate

Manufacturer's advertised maximum flow rate.