Ductile Iron Flanged Backflow Preventer

Product introduction: 

DF41X Series backflow preventer is a hydraulic control combination device that strictly limits the one-way flow of water in pipelines. Its function is to prevent medium backflow in pipelines under any working conditions, in order to avoid backflow pollution. The working principle of backflow preventer is to use the medium to flow through the inlet check valve and reduce pressure due to mechanical resistance and loss of flow head, so that the pressure is higher than the pressure in the discharge valve chamber. The pressure in the upper part of the discharge valve diaphragm is pressure, and the pressure in the upper part of the diaphragm is greater than the resistance in the discharge valve chamber and spring. The discharge valve remains closed, and the medium flows normally. When the pressure difference between the pressure and the discharge valve chamber is less than 0.02Mpa, the medium is in a critical state of backflow. At this time, the pressure in the upper part of the discharge valve diaphragm is less than the pressure in the discharge valve chamber and spring, and the discharge valve automatically opens, discharging the backflow medium out of the pipe. At the same time, a large amount of air enters the valve chamber, forming an air partition to prevent medium backflow. When the pressure difference Automatic shutdown. When the water pressure in the pipeline network behind the valve rises beyond the water pressure at the front end of the valve, if the second one-way check valve is well sealed and the water will not flow back, the drain valve will close and not release water. When the seal of the second one-way check valve fails and leaks, the drain valve will open to drain and release pressure.
 

Product technical parameter:

Product features:

1. DF41X series backflow preventor adopts the principle of pressure reduction to achieve low resistance, the actual water loss during normal operation at an economic flow rate is only 1.8-2.5 meters.
2. The backflow preventer has a compact structure and short size. The two-stage independent check valve has a small flow resistance, can open and close, and can prevent damage to the valve and pipeline caused by sudden increase in back pressure. It has a silent function.
3. The discharge pressure of the drain valve is adjustable, with little interference from pipeline fluctuations, and reliable opening and closing.
4. The design of dual membranes can prevent backflow pollution caused by membrane damage.
5. The structure of the air partition with dual inlet and outlet channels ensures that the intake and drainage in the partition chamber do not affect each other, and there is no problem of poor drainage or poor drainage. It can limit the possibility of pressure water backflow or siphon backflow.
6. The built-in control pipeline system avoids the danger of exposed bypass pipes being easily stolen and damaged, and can prevent people from using them for poisoning and other destructive activities. It is also aesthetically pleasing to use.
7. Can be tested and repaired online.