Suzhou Kaitianfu Machinery Co., Ltd

Valve Seat: The detachable surface parts in valve are used to support the valve spool in the fully closed position and constitute a sealed part. Generally, valve seat diameter is the maximum flow diameter of the valve. Elastic sealing material and small actuator's thrust force is used to obtain tight seal of air bubble, compression valve seat's sealing stress elastically deforms the material and squeezes it into the rough surface of the matching metal part to block all leakage paths. The permeability of material is a basis for small amount of leakage for fluid. The seal must be carefully fixed to prevent cracking and air leakage due to differential pressure. Bonding soft valve seat to metal part is one way, but it cannot completely solve the problem because the bond breaks and fails when exposed to thermal shock. A sufficiently large pressure drop will destroy the bonding material. Thermal spraying technology ultrasonic spraying equipment is used to optimize thermal spraying process so that the denseness of coating can meet the gas sealing requirements under up to 140MPa, the porosity of coating <1%, the bonding strength exceeds 75MPa, the hardness can reach HV1500 and the hardness uniformity fluctuates by no more than HV100; the product surface after coating can reach mirror surface, with roughness less than Ra0.1, and flatness no more than 2 bands, which can effectively reduce the coefficient of friction between Valve Gate and valve seat and improve its service life.