Search results
Results from the WOW.Com Content Network
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 ...
A fire hydrant, fireplug, firecock ... Canada A reduced pressure zone device is used to prevent backflow when supplying water to a ... This design is known as a "dry ...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Donate; Pages for logged out editors learn more
Water pressure may fail or be reduced when a water main bursts, pipes freeze, or there is unexpectedly high demand on the water system (for example, when several fire hydrants are opened). Reduced pressure in the pipe may allow contaminated water from the soil , from storage, or from other sources to be drawn up into the system.
Backflow occurs for one of two reasons, either back pressure or back siphonage. [1] Back pressure is the result of a higher pressure in the system than in its supply, i.e. the system pressure has been increased by some means. This may occur in unvented heating systems, where thermal expansion increases the pressure.
Gridded systems provide multiple paths for the water to travel to any point in the system, reducing pressure losses in the system. Most design standards require application of the Hazen-Williams method for determining frictional pressure losses through the piping network as water passes through it. Tree and Loop systems are simple enough that ...
Get answers to your AOL Mail, login, Desktop Gold, AOL app, password and subscription questions. Find the support options to contact customer care by email, chat, or phone number.
Water cannot flow from the sink to the tap in normal circumstances, even if the water supply loses pressure. An air gap, as related to the plumbing trade, is the unobstructed vertical space between the water outlet and the flood level of a fixture. [1]