Soft and hard sealing butterfly valve features and differences

  The hard seal butterfly valve is made of metal material or harder other materials called "hard seal". This seal has poor sealing performance, but high temperature resistance, wear resistance and good mechanical properties. For example: 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, spraying alloy).

  Hard-seal butterfly valve: The two sides of the sealing pair are made of metal material or other hard materials. It is called "hard seal". This seal has poor sealing performance, but it is resistant to high temperature, abrasion and mechanical properties. 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).

  Soft seal: the side of the seal pair is made of metal material, and the other side is made of elastic non-metallic material. It is called "soft seal". This seal has good sealing performance, but it is not resistant to high temperature and easy to wear. Poor mechanical. For example: steel + rubber; steel + PTFE [wiki] polyethylene ;

  The soft-sealed disc valve means that one side of the sealing pair is made of a material having a relatively low hardness. Generally, the soft sealing seat is made of a non-metallic material having a certain strength, hardness and temperature resistance, and the sealing performance is good, and can be done. Zero leakage, but the life and temperature adaptability is 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.

 The soft seal can not meet the process requirements for a part of corrosive materials, and the hard seal 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 have a short service life;

  The hard seal has a long service life, but the seal is relatively inferior to the soft seal.
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