Automatic return valve structure and working principle Automatic return valve installed in the boiler feed pump outlet to prevent backflow of water, and to ensure that there is a certain minimum recycle bypass flow. The feed water pump three-way valve by the valve body and the valve cover connected through the flange, in order to facilitate installation, maintenance and repair of seat grinding, changing the original one-piece structure. Valve seat and the valve are hard alloy surfacing to ensure that the erosion, wear and sealing, extending the service life. Body seal for the rubber seal seal to ensure the reliability of the seal. Valve body import and export and recycling system exports are flanged, easy disassembly and maintenance. This valve sets the components in one, can be completed four different Automatic return valve function: Automatic return valve installed in the pump outlet, but it can automatically detect the size of the pump flow, and through the pilot valve to the recirculation control valve action (instead of the indirect indirect control of the pressure by the recirculation action). The valve body is equipped with recirculation decompression facilities, which can make the high-pressure medium flow around the small diameter several times and consume a large amount of energy to reduce the pressure of the recirculation system. This valve only recirculates to cool the pump when the flow rate is very low. When the pump is in normal operation, it does not recirculate, thus saving the energy and water energy consumed by continuous recirculation in the past. This automatic recirculation control valve does not require electrical wiring and does not require two regulating valves in series (one for regulation and one for shut-off) and minimizes high-speed flow cords and erosion easily created by high pressure systems. Automatic return valve works as the main valve to reduce flow, the main valve flap in the direction of the spring force to move to the seat, when the flow through the pump to achieve the minimum flow, the valve flap guide pilot valve so that the pressure on the piston Decrease, the piston moves to open the bypass valve (the fluid through the bypass valve is depressurized by the bypass valve flap) to allow for a small amount of recirculation of the pump during low-load operation to ensure pump cooling . When the flow rate exceeds the pump minimum flow, the main valve flap up, so that the pilot valve is closed, cut off bypass. From the fundamental solution to the previous system is not running smoothly, noise, short life expectancy, expensive, installation and maintenance inconvenience shortcomings. ã€Print】 ã€Close】