Soft Seal Butterfly Valve
Hard Seal Butterfly Valve
Hard seals are made of metal, such as metal gaskets, metal rings, etc., and sealing is achieved through friction between metals. Therefore, the sealing performance is relatively poor, but our ZFA valve manufactured multi-layer hard seal triple eccentric butterfly valve can achieve zero leakage . Soft seals are made of elastic materials, such as rubber, PTFE, etc. For some materials with high temperature and high pressure, which cannot meet the process requirements, hard-sealed butterfly valves can solve the problem.
The differences between hard-sealed butterfly valves and soft-sealed butterfly valves:
1. Structural differences: Soft seal butterfly valves are mostly centerline butterfly valves and double eccentric butterfly valves, while hard seal butterfly valves are mostly single eccentric butterfly valves and triple eccentric butterfly valves.
2. Temperature resistance: Soft seal is used in normal temperature environment, Rubber for -20℃~+120℃, PTFE for -25℃~+150℃. Hard seal can be used in low temperature, normal temperature, high temperature and other environments, LCB for -29°C -+180°C, WCB ≤425°C, Stainless Steel≤600°C.
3. Pressure: Soft seal low pressure-normal pressure PN6-PN25, hard seal can also be used in medium and high pressure conditions such as PN40 and above.
4. Sealing performance: Soft seal butterfly valve and triple eccentric hard seal butterfly valve have better sealing performance. Triple eccentric butterfly valve can maintain good zero leakage seal in high pressure and high temperature environment. However, it is difficult for ordinary hard-sealed butterfly valves to achieve zero leakage.
5. Service life: Soft-sealing butterfly valves are prone to aging and wear, and their service life is expected to be short. Hard-sealed butterfly valves have a long service life.
In view of the above characteristics, the centerline butterfly valve is suitable for use in fresh water, sewage, seawater, salt water, steam, natural gas, food, medicine, petroleum products, bidirectional opening and closing of ventilation and dust removal pipelines, and various acids in general temperature, pressure and non-corrosive media scenarios. Alkali and other pipelines require complete sealing, zero gas leakage test, and operating temperature of -10~150℃. The hard-sealed butterfly valve is suitable for scenarios with high temperature, high pressure and corrosive media, such as regulating and throttling devices in oil, gas, acid and alkali pipelines such as urban heating, gas supply, water supply, petroleum, petrochemical, chemical industry, metallurgy, and electric power. and other fields. It is a good replacement for gate valves and globe valves.