Backflow preventer, also called the anti-pollution isolating valve is used to prevent a potable water pipeline backflow pollution safety device. In China, with the accelerating urbanization, municipal water pipes, water pipes for extending the backflow prevention measures Settings required specification and also more and more strictly.
No negative supply equipment as a pipe from the municipal water pressure pipe directly or other secondary pressurized water supply install docking, when on the takeover equipment may appear online "or" backsiphonage backflow of back pressure backflow "phenomenon, should be in equipment connect feed on setting backflow pollution device. But now, as our main backflow pollution decompression of the device type backflow preventer (referred to as "in the domestic existing backflow preventer) as big volume, expensive, health performance low carbon steel casting (most of ontology and ordinary rubber seal), head loss (reduced pipe pressure), therefore, in engineering application more difficult. Health, low resistance of stainless steel backflow preventer can make the above problems are solved, simply introduces below the backflow preventer without pressure water equipment in the application.
Stainless steel a backflow preventer is strictly limited the pressure of water can one-way pipe flow control, hydraulic (see chart 1) is by two independent check valve and a hydraulic control valves, drainage pipeline is strictly limited is a one-way flow, water pressure effectively prevent backflow. Among them, the two independent level check valve temporarily fill check valve and check valve, water hydraulic control for automatic drain valve discharge valves. Water inlet check valve and check valve adopts two coaxial disc shaft center, and the same, including inlet check valve disc check seals from its spring force, water check valve disc check from the outlet pressure sealing force. Hydraulic control drain valve opening and closing of the controlled YuJinShui pressure and intermediate valve chamber pressure changes, and drain valve bonnet seat in the spring force balance Settings. When water check valve leakage or water pressure of the valve pressure, or less than the water pressure, water pressure valves, check valves will drain valve leakage in the hydraulic pressure difference under automatic drainage, air partition, prevent backflow pollution. Valve cartridge valve refers to water from water seal check valves to check the sealing parts between cavity.
Stainless steel backflow preventer is the function in any conditions strictly prevent backflow (back) or contaminated. To prevent backflow pollution refers to the body cavity flow into the water are not allowed to check the sealing surface of the water, with complete avoid in any conditions for water and pollution of backflow back.
Stainless steel backflow preventer to prevent backflow used for drinking water pollution, and nominal diameter pipeline connecting pipe with front of nominal diameter, working pressure rating the same should be not less than connecting pipe pressure rating.
In no negative supply equipment, when may directly in the municipal water pipe joint road should appear in the backflow pollution without pressure water equipment imported stablized compensator after the filter set before the backflow preventer stainless steel, and install a valve. Backflow preventer should choose stainless steel pipe, depending on the use of regional and USES. Example: when no negative supply equipment as municipal water pipe pressure, and midway through the pipe joint for municipal water pipe, water pipe in the same properties, appear not exist pollution problem, backflow when not to install the steel therefore backflow preventer.
When the equipment is in negative feed water meter, must have faith in stainless steel water should fill the backflow preventer.
Stainless steel pressure backflow preventer is installed in the water before the equipment should be flushed water pipe (in pipe should not remain sediment, welding slag, bolts, etc), and should in sundry stainless steel backflow preventer is installed in the water, in case the sundries clinging, filter and disc friction card lax produce leakage, closed or cause hydraulic control discharge water drain valve misoperation. In addition, stainless steel backflow preventer must be installed horizontally (arrow valve bonnet upward, downward outfall location), the installation of the environment should be clean and not be submerged, and have enough space, installation and maintenance of water and to facilitate timely find relief or malfunction. In addition, the hydraulic control drain valve shall be indirectly drainage and drainage directly connected, drain off the ground height should be greater than in installation location, and 300mm should set drainage facilities.
Currently on the market without pressure water equipment for stainless steel fittings, most of the equipment supply all that does not produce secondary pollution. If use carbon when backflow preventer in use process of water contamination, therefore, no negative supply equipment use stainless steel backflow preventer.
Stainless steel backflow preventer is the function in any conditions strictly prevent backflow due to water and pollution of backflow. When using should be reasonable design, excellent manufacture, while ensuring safe and reliable, and ensure the quality.
In no negative water used in equipment, low resistance of health backflow preventer stainless steel, can effectively prevent the backflow of water pollution, raise the quality of equipment safeguard ability and municipal water pipe pressure, and actively promote efficiency for no negative water technology, thoroughly solve the pollution of municipal water provides the reliable technical measures.