The Differences Between Soft Seal Butterfly Valve And Hard Sear

Hard seal butterfly valve is called "hard seal" when both sides of the seal are made of metal or other hard materials. The sealing function of this kind of seal is poor, but it is resistant to high temperature, wear and tear, and has good mechanical function. Such as: steel + steel; steel + copper; steel + graphite; steel + alloy steel; here the steel may also be cast iron, cast steel, alloy steel may also be welded, sprayed alloy. 

Soft seal butterfly valve: the two sides of the sealing side is a metal material, the other side is a flexible non-metallic material is called "soft seal". The sealing function of this seal is better, but it is not resistant to high temperature, easy to wear, and the mechanical properties are poor. Such as: steel + rubber; steel + teflon polyethylene, etc. . Soft seal seat selected with a certain strength, hardness and temperature resistance of non-metallic materials manufacturing sealing function is good to be able to do zero leakage but the life and adaptability to temperature is relatively poor.

The hard seal is made of metal and the sealing function is relatively poor, although some manufacturers claim to be able to do zero leakage. Soft seal can not satisfy the process requirements for some corrosive materials, hard seal can deal with these two seals can complement each other in terms of sealing soft seal is relatively good, but now the hard seal sealing can also meet the corresponding requirements. The hard seal has a long service life, but the sealability is relatively worse than the soft seal.

The differences in structure are mainly as follows.

1, Soft seal butterfly valves are mostly midline type hard seal butterfly valves are mostly single, double, and triple migraine butterfly valves.

2, temperature resistance Soft seal is used for normal temperature environment. Hard seal can be used in low temperature, room temperature, high temperature environment.

3, Pressure: Soft seal low pressure - atmospheric pressure Hard seal can also be used in high pressure and other working conditions.

4, Sealing function: Soft seal and triple migraine hard seal butterfly valve sealing function is relatively good triple migraine butterfly valve can adhere to good sealing under high pressure and high temperature environment. 

In view of the above features, soft seal butterfly valve is suitable for bi-directional opening and closing of ventilation and dust removal pipeline and regulating water treatment, light industry, petroleum, chemical industry, etc. Hard seal butterfly valves are mostly used for heating, gas supply, and gas, oil, acid and alkali environments. 

With the widespread use of butterfly valves, the features of easy installation, easy repair and simple structure are becoming more and more obvious.