Safety valve is an automatic pressure relief device, which is the most important one of the pressure vessel. Its function is: when the pressure exceeds a certain value, the pressure of the medium itself automatically opens the valve. When the pressure drop to the allowable value, the valve will automatically shut down, so that the pressure in the container is always lower than the upper limit of the allowable pressure, automatic control of the overpressure and may occur, so the safety valve is also known as the ultimate protection device of the pressure vessel.
     Safety valve for the spring type safety valve, its working principle is: the pressure is greater than the medium role in the normal pressure valve core, the valve is closed, when the pressure exceeds the allowable pressure, the spring is compressed, the valve automatically opens, the valve is automatically opened, the media release, decompression; when the pressure back to normal, the spring pressure and the valve seat, the valve automatically shut down.