When this kind of safety valve is in normal operation of the boiler, in addition to pressing the valve core on the valve seat by the spring, the valve core is also pressed by the pressure on the upper part of the piston by the compressed air, which does not improve the tightness of the safety valve. Reduce leaks and prolong use. When the boiler pressure rises to the operating pressure of the safety valve, under the action of compressed air, the safety valve opens quickly to release steam. When the pressure is reduced, the compressed air can be switched to the upper part of the piston to close the safety valve. Since the safety valve can be opened and closed quickly, the degree of blowing damage to the sealing surface during the opening and closing process can be avoided or reduced.
The piston type disc spring safety valve has the advantages of sensitive opening and closing, good tightness, and long service life, and is used in some large-capacity boilers.