Comparison of hard seal PVC butterfly valve and soft seal Plastic butterfly valve
A PVC butterfly valve hard seal means that the sides of the seal pair are made of a metallic material or a harder other material called a "hard seal." This seal has poor sealing performance, but is resistant to high temperatures, abrasion and mechanical properties. The soft seal means that the side of the seal pair is made of a metal material, and the other side is a non-metallic material called a "soft seal". The seal has good sealing performance, but is not resistant to high temperature, is easy to wear, and has poor mechanical properties.
The soft seal seat is made of non-metallic material with certain strength, hardness and temperature resistance. It has good sealing performance and can be made to zero leakage, but its service 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 to be able to make zero leakage. Soft seals can not meet the process requirements for a part of corrosive materials, hard seals can be solved! These two seals can complement each other, and the soft seal is relatively good in terms of sealing, but now the seal of the hard seal can meet the corresponding requirements. The advantage of the soft seal is that the sealing performance is good, and 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 seal is relatively inferior to the soft seal.
The structural differences are mainly as follows:
1. Structural difference: soft seal butterfly valves are mostly medium-line type hard seals, mostly single eccentric, double eccentric, triple eccentric butterfly valve
2, temperature resistance: soft seal for normal temperature environment. Hard seal can be used in low temperature, normal temperature, high temperature and other environments
3, pressure: soft seal low pressure - normal pressure, hard seal can also be used in medium and high pressure working conditions pneumatic soft sealing butterfly valve
4, sealing performance: soft seal and three eccentric hard seal butterfly valve sealing performance is better, three eccentric butterfly valve can maintain a good seal in high pressure and high temperature environment.
In view of the above characteristics, the hard seal butterfly valve has been widely used in many fields such as petroleum, chemical, metallurgy, and hydropower as a component for implementing the on-off and flow control of the pipeline system. The soft sealing butterfly valve is suitable for two-way opening and closing and regulation of ventilation and dust removal pipelines, water treatment, light industry, petroleum, chemical industry and other industries. Hard-sealed butterfly valves are mostly used for heating, gas supply, and gas, oil, acid and alkali environments.
