When the regulating valve operates under complex working conditions, it will cause serious corrosion, cavitation, erosion, blockage and scratch, which will cause serious damage to the sealing surface of the regulating valve, resulting in unreliable sealing of the regulating valve and short sealing life, which has become a stubborn disease of the domestic regulating valve for decades. After the full-function ultra-light control valve breaks through the problems of bulkiness and incomplete function of the control valve, we are committed to breaking through the difficult sealing under complex working conditions.

1、 What is a complex working condition and the problems it causes

1. High pressure, large differential pressure - serious erosion or cavitation, affecting the seal life.

2. High temperature and large temperature difference - severe thermal expansion and contraction change the fitting properties of the assembly at normal temperature, resulting in leakage, sometimes blocking, making it difficult to move, even being "blocked".

3. Unclean media - causing serious erosion, blocking, core seat scratch, affecting the action and sealing.

4. Corrosive medium - causes corrosion damage to the contact material.

5. Grade VI hard seal cutoff - especially the cutoff with large pressure difference, the core and seat must be closed tightly. At the moment of opening, the sealing surface will be pulled due to friction.

To sum up, in the above-mentioned harsh working environment that produces serious cavitation, erosion, corrosion, expansion and contraction, blockage, scratch, etc., Class VI hard seal cutoff is even more difficult, and has become a stubborn disease of domestic control valves that has not been overcome for decades.

2、 Reliability analysis of traditional seal structure

1) The soft seal is soft to the soft seal material - it is easy to seal, because the material is very soft and reliable.

2) The soft seal is slightly better than (1) for stainless steel, but the seal is still unreliable.

3) Stainless steel is slightly better than stainless steel (2), but the hardness of stainless steel is still very low (HRC20~25), and the sealing is still unreliable.

4) Multi-layer sealing valve seat - stainless steel sheet is overlapped with soft material, and the sealing reliability is similar to (2) (3) above, but the temperature resistance is improved.

5) Surfacing wear-resistant alloy - generally surfacing STELLITE alloy is a good sealing material at present. However, its hardness is still not high (HRC40~45), and it is still not suitable for the harsh conditions of complex working conditions.

6) Ceramic seal - high hardness, lack of toughness, easy to crack, even crack before use.