Products: valve opening and closing pieces by medium flow and forces to turn on or off, in order to prevent the media back check valve called. Check valves are automatic valves, mainly used for one-way flow of media channels, only allowing media to flow in one direction, in order to prevent accidents. How it works: check refers to rely on the flow of the medium itself automatically open and close the valve, the valve is used to prevent the media back, also known as check valves, check valves, backflow valve, and back pressure valve. Check valves are an automatic valve, whose main role is to prevent the media back, to prevent the pump and drive motor reversal, and discharge the container media. Pressure valve which can also be used to exceed the system pressure may rise auxiliary system supplies the pipeline. Check valve can be divided into the swing check valve (depending on the focus of the rotation) and lift check valves (axial movement). Check the media's role is only allowed to flow in one direction, and stop the flow in the opposite direction. Usually the valve is automatically work in a direction of flow of the fluid pressure effect, the valve opens; opposite direction of fluid flow from the fluid pressure and the valve from the coincidence of acting on the valve seat, thereby cutting off the flow. Application: the need to prevent the reverse flow of the medium pipe. Note: 1. The purpose of this device is to prevent the gas valve back when the fan stops. 2, the valve device range, the wind speed does not require duct drizzle 8 m / sec. 3, the installation is equipped with a heavy hammer horizontal, vertical installation without hammer, when ordering installation. Our company specializes in the production of central air conditioning and ventilation, smoke ventilation various damper: dampers, fire control valve, exhaust valves, smoke damper, manual control valve, check valve, residual pressure valves, pressure delivery outlet, leafy exhaust port, exhaust port plate, a variety of remote control valve. The company is strong in technology, superior product quality, credit protection, low prices. Our call to discuss!