The Difference between Pneumatic Hard Sealing Butterfly Valve and Pneumatic Soft Sealing Butterfly Valve
Pneumatic hard-seal butterfly valve refers to a “hard seal” in which both sides of the seal pair are made of metal materials or other harder materials. This kind of seal has poor sealing performance, but high temperature resistance, wear resistance, and good mechanical properties. Such as: steel + steel; steel + copper; steel + graphite; steel + alloy steel; (the steel here may also be cast iron, cast steel, alloy steel may also be surfacing, sprayed alloy).
Pneumatic soft-seal butterfly valve refers to the one side of the sealing pair is made of metal materials, and the other side is elastic non-metallic materials, which is called “soft seal”. This kind of seal has good sealing performance, but it is not resistant to high temperatures. Easy to wear and poor mechanical properties. Such as: steel + rubber; steel + PTFE; etc. The soft sealing seat is made of non-metallic materials with certain strength, hardness and temperature resistance, and the sealing performance is good, and it can be done to zero Leakage, but life and temperature adaptability are relatively poor. The hard seal is made of metal, and the sealing performance is relatively poor, although some manufacturers claim that it can achieve zero leakage. The soft seal cannot meet the process requirements for some corrosive materials, and the hard seal can solve it! These two types of seals can complement each other. In terms of tightness, the soft seal is relatively good, but now the tightness of the hard seal can also meet the corresponding requirements! The advantage of the soft seal is good sealing performance, but the disadvantage is that it is easy to age, wear, and has a short service life. The hard seal has a long service life, but the tightness is relatively worse than that of the soft seal.
The main structural differences between pneumatic soft-sealed butterfly valve and pneumatic soft-sealed butterfly valve are as follows:
- The difference in structure: Pneumatic soft-seal butterfly valves are mostly centerline-type hard-seal butterfly valves, mostly single eccentric, double eccentric and triple eccentric butterfly valves
- Temperature resistance: Pneumatic soft sealing butterfly valve is used in normal temperature environment. Hard seal can be used in low temperature, normal temperature, high temperature and other environments
- Pressure: Pneumatic soft sealing butterfly valve, low pressure-normal pressure, hard sealing can also be used in medium and high pressure conditions
- Sealing performance Pneumatic soft sealing butterfly valve and pneumatic hard sealing butterfly valve have better sealing performance. Pneumatic soft sealing butterfly valve can maintain a good seal under high pressure and high temperature environment.
In view of the above characteristics, the pneumatic soft sealing butterfly valve is suitable for two-way opening and closing and adjustment of ventilation and dust removal pipelines, water treatment, light industry, petroleum, chemical and other industries. Hard-sealed butterfly valves are mostly used in heating, gas, gas, oil, acid and alkali environments.
