Ad
related to: two way water tap drain assembly system
Search results
Results from the WOW.Com Content Network
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.
In the UK this type of tap normally has a wheel-shaped handle rather than a crutch or capstan handle. Cone valves or ball valves are another alternative. These are commonly found as the service shut-off valves in more-expensive water systems and usually found in gas taps (and, incidentally, the cask beer taps referred to above).
The visible water surface in a toilet is the top of the trap's water seal. Each fixture drain, with exceptions, must be vented so that negative air pressure in the drain cannot siphon the trap dry, to prevent positive air pressure in the sewer from forcing gases past the water seal, and to prevent explosive sewer gas buildup.
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.
According to the International Residential Code 2003, an air gap length must meet the requirements of being two times the effective inner diameter of the pipe (2×D) in order to be sufficient. [2] A standard widely use in the United States is: A112.1.2 Air Gaps in Plumbing Systems (For Plumbing Fixtures and Water-Connected Receptors)
Because certain combinations of check valve failure and/or system backpressure cause the relief valve to discharge, the device must be mounted in a location where the drain will not become flooded. An example of where backflow would harm the water supply is the use of well washing devices inside underground sewerage pumping stations.
A sewer pipe is normally at neutral air pressure compared to the surrounding atmosphere.When a column of waste water flows through a pipe, it compresses air ahead of it in the system, creating a positive pressure that must be released so it does not push back on the waste stream and downstream traps, slow drainage, and induce potential clogs.
Stopcocks are used to grossly regulate the flow of tap water in residential and commercial services. One is found at the junction of a water main and the branch leading to an individual service (allowing the service to be isolated from the main trunk), and a second inside the structure (allowing its plumbing to be isolated from the branch line leading into it).
Ad
related to: two way water tap drain assembly system