Butterfly valve should we use soft seal or hard seal

Butterfly valve, also known as flap valve, is a kind of regulating valve with simple structure. Butterfly valve that can be used for on-off control of low-pressure pipeline medium means that the closing member (disc or butterfly plate) is a disc, which rotates around the valve shaft to achieve opening and closing. of a valve.

Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. It mainly plays the role of cutting and throttling on the pipeline. The butterfly valve opening and closing part is a disc-shaped butterfly plate, which rotates around its own axis in the valve body to achieve the purpose of opening and closing or adjustment.

Butterfly valve soft seal:

The two sides of the sealing pair are made of metal material, and the other side is made of elastic non-metallic material, which is called "soft seal". The sealing performance is good, but it is not resistant to high temperature, easy to wear, and has poor mechanical properties. Such as: steel rubber, steel tetrafluoroethylene, etc. The soft sealing seat is made of non-metallic materials with certain strength, hardness and temperature resistance, which has good sealing performance and can achieve zero leakage, but has poor service life and temperature adaptability.

Hard seal:

Both sides of the sealing pair are made of metal materials or other hard materials, which are called "hard seals". The sealing performance is poor, but high temperature resistance, wear resistance, and good mechanical properties. Such as: steel, copper, steel graphite, steel alloy steel; (the steel here can also be cast iron, cast steel, alloy steel or surfacing, spraying alloy).

The hard seal of butterfly valve is made of metal, and the sealing performance is relatively poor. Soft seal can not meet the process requirements of some corrosive materials, hard seal can solve it! The two seals can complement each other. As far as sealing is concerned, soft seals are relatively good, but now hard-sealed seals can also meet the corresponding requirements! The advantage of soft seal is good sealing performance, but the disadvantage is easy aging, wear and short service life. Hard seals have a long service life, but their sealing performance is worse than that of soft seals.