Valve Backflow Preventer
Backflow preventers protect against reversed flow caused by backpressure or backsiphonage. Backsiphonage occurs when the supply pressure drops below atmospheric pressure, thus creating a vacuum. Backpressure occurs when the supply pressure drops below the residual pressure in the downstream piping. Either of these conditions can result in backflow. When cross-connections or potential cross-connections exist, backflow can result in pollution or contamination of the potable water supply.
A double-check valve assembly may be used under continuous pressure and protect against both backsiphonage and back-pressure conditions. It consists of two single check valves coupled within one body and furnished with test cocks and two tightly-closing gate valves.
Double-check valves have a test capability feature that gives this device a big advantage over the use of two independent check valves. Double-check valves can be readily tested to determine that both valves are functioning properly and are not fouled by debris. Each check valve is spring-loaded closed, and requires approximately 1 psig of pressure to open. Spring loading provides the ability to "bite" through small debris and still maintain the seal. Spring loading is a protection feature not prevalent in unloaded swing check valves.
Double checks are commonly used to protect against low-to-medium hazard installations, such as in food-processing steam kettles and in apartment projects.
Manufactures and Suppliers Participating in OPUS
Apollo Valves
- Apollo Valves has been the global leader in valve innovation for over 75 years. We are dedicated...
(click for details) Embassy Group LTD
- Embassy Group Ltd. is a 100 percent member-owned, 3.2 billion dollar corporation consisting of...
(click for details) F.W. Webb Company
- F.W. Webb Company is a multi-faceted distributor of Plumbing and Heating, HVAC and Controls,...
(click for details) Ferguson
- Ferguson specializes in plumbing and heating, industrial pipe, valves, fittings, underground...
(click for details) Johnson Controls, Inc.
- Johnson Controls manufactures, installs, integrates, services and operates systems that manage...
(click for details) NIBCO INC.
- Founded in Elkhart, Indiana in 1904, NIBCO INC. is a leading provider of a diverse range of flow...
(click for details) Tyco/GRINNELL Mechanical Products
- Tyco Fire & Building Products manufactures the Grinnell® line of grooved products...
(click for details) Watts
- Watts Regulator Company provides maximum value for your money and exceeds your needs by...
(click for details) WinWholesale, Inc.
- WinWholesale is comprised of over 550 wholesale distribution locations that sell high-quality...
(click for details) Zurn Industries, LLC
- Zurn markets and manufactures roof/floor drains, interceptors, cleanouts, water closet carriers,...
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