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A reduced pressure zone device (RPZD, RPZ, or RPZ valve) is a type of backflow prevention device used to protect water supplies from contamination. RPZDs may also be known as reduced pressure principle (RP), reduced pressure principle backflow prevention devices , [ 1 ] [ 2 ] reduced pressure zone assemblies (RPZA), [ 3 ] or reduced pressure ...
The importance of valve leakage depends on what the valve is controlling. For example, a dripping tap is less significant than a leak from a six-inch pipe carrying high-pressure radioactive steam. In the United States, the American National Standards Institute specifies six different leakage classes, with "leakage" defined in terms of the full ...
Backflow prevention device. The simplest, most reliable way to provide backflow prevention is to provide an air gap.An air gap is simply an open vertical space between any device that connects to a plumbing system (like a valve or faucet) and any place where contaminated water can collect or pool.
Sprinkler systems installed by sprinkler fitters can include the underground supply as well as integrated overhead piping systems and standpipes. The fire suppression piping may contain water, air (in a dry system), antifreeze, gas or chemicals as in a hood system, or a mixture producing fire retardant foam .
A double check valve or double check assembly (DCA) is a backflow prevention device designed to protect water supplies from contamination. [1] It is different from the two-way check valves (sometimes erroneously referred to as double check valves) used in air brake systems on heavy trucks which select from the highest pressure source.
Underground irrigation is provided by the WaterMaster product line that includes sprinkler timers, valves, accessories, tools and sprinkler heads. The DripMaster line is designed for delicate drip-water applications in areas with special needs (e.g., gardens, flower beds, container plants, trees and ground cover). Hose-end applications are met ...
Larner–Johnson Valve: needle control valve often in large sizes used in water supply systems; Leaf valve: one-way valve consisting of a diagonal obstruction with an opening covered by a hinged flap; Line blind valve: a thin sheet oriented perpendicular to the pipe. The sheet has a solid end and a flow-through end; sliding it from one position ...
Most automatic irrigation valves are diaphragm valves in which the water above the diaphragm must be discharged for the valve to open. In a hydraulic system, the controller and valves are connected via small plastic tubes approximately 4 mm (¼ in) in diameter. The controller opens the tube connected to the valve, allowing that valve to open.