Historical
ASSE 1019-2004
Performance Requirements for Vacuum Breaker Wall Hydrants, Freeze Resistant, Automatic Draining Type
These devices are to supply potable water without danger of damage to the device due to freezing & to provide protection of the potable water supply from contamination due to back siphonage or back pressure less than or equal to 3 meters (10 feet) of head pressure. The devices shall be classified as: Type A: Automatically drain the water when the water supply is shut off and the hose removed to prevent damage from freezing; Type B: Automatically drain the water with a hose removed or attached, end nozzle closed, & the hydrant valve closed; Type C: Same as Type A. Backflow prevention is achieved by alternate principle of holding pressure versus relieving pressure.
Content Provider
American Society of Sanitary Engineering [asse-sanitary]
