Wire backflow preventer

First, the product introduction:
       HS11X-16T wire backflow preventer is to repair the pipeline and power off, the tap water is often interrupted, once the power supply is restored, the tap water becomes yellow and dirty, which is due to the fire pipe in the process of water cut Dead water and rust water in the unused pipes of unoccupied buildings or water pipes are caused by backflow. In order to allow residents to drink clean water, the backflow preventer can effectively prevent the occurrence of dirty water inversion under the above conditions, which not only ensures the safety of drinking water but also saves water resources. According to the introduction of the China Building Standard Design Institute, the Ministry of Construction has revised the relevant national standards and installed “backflow preventers” on the building water supply pipes.  

 Second, the structure of the product: the
       backflow preventer is composed of a two-stage non-return system and a drainage and pressure relief system. The upper chamber of the drain pressure relief system is connected to the inlet end of the first stage check system. 
       The first and second check systems are mainly composed of a valve body, a water inlet joint, a valve flap, a gasket, a spring, and the like. 
       The drain pressure relief system is mainly composed of a valve cover, a diaphragm, a valve core, a gasket, a drain port, a spring, an air blocker, etc., and the outlet of the air blocker must be connected to the drain pipe network or the sewer.

 Third, the working principle: the
       backflow preventer is to add a drainage pressure relief device in the secondary check system, so that even if the secondary check seal is destroyed at the same time, it can also play a role in preventing backflow pollution. How it works: 
       1. Normal water supply: 
       a. Clean municipal water from the first-stage check system through the drain to the second-stage check system outlet to supply water to the user. The first-stage check system imports high-pressure water into the drain diaphragm. The cavity, and the lower diaphragm cavity communicates with the outlet of the first stage check valve (the inlet of the second stage check valve), because of the certain pressure difference ΔP1=0.035MPa, pushing the valve flap down, the drainer is closed, the backflow preventer Normal water supply; 
      b. When there is no user in the pipeline after the valve, the water is still. If the inlet pressure remains unchanged, there is a pressure difference before and after the drain, and the drain is still closed. If the inlet pressure drops, and the intermediate chamber and the valve front pressure difference ΔP1 ≤ 0.022 MPa, the drain control spring pushes the valve core to open the drain. The chamber is drained to maintain ΔP1 at 0.035 MPa. 

       2. When the seal fails: 
       a. After the backflow preventer, the pressure of the pipe network rises. When the inlet pressure of the valve is exceeded, if the second check valve is sealed and there is no leakage, the high pressure water will not flow backward, and the drain diaphragm will maintain the original pressure up and down. Poor, the drain is closed and no pressure is released. When the second-stage check valve seal breaks and leaks, the pressure rises before the second-stage check valve, causing the differential pressure difference between the upper and lower drains of the drainer to be reduced, the drainer to open, and the drain to be released; at this time, as in the first stage The return valve is sealed and destroyed at the same time. Since the high-pressure water backflowed by the second-stage check valve has been released from pressure and pressure, it will not flow back to the first-stage check valve. 
       b. When the post-valve pressure is higher than the pre-valve pressure, if the water supply pressure drops continuously, the upper pressure of the drain diaphragm decreases, and the safety drain control spring pushes the spool to open the drain drain. When the inlet pressure drops to zero or negative pressure, the drain is fully opened, the water is drained, and air enters the vacuum chamber from the drain, thereby preventing the phenomenon of siphon backflow.

       3. The valve opening pressure is ≤0.07MPa, the specification is in the range of 0.06~0.1MPa, and the working pressure difference of the inlet check valve is 0.035MPa. 

Main shape and installation size: