Butterfly valve is one kind of industrial valves which uses a circular disc as an opening and closing part(usually we called it valve disc or valve plate), that disc rotates with the valve stem to open,close and adjust the fluid channel. The disc plate of the butterfly valve is installed in the diameter direction of the pipeline. The earlier application of butterfly valve started with the air volume baffles on flues or chimneys, and were also used in low pressure systems such as ventilation or supply air. In recent years, metal sealed butterfly valves have developed rapidly. With the application of high temperature resistance, low temperature resistance, strong corrosion resistance, strong erosion resistance, high density alloy steel material in butterfly valves, metal sealed butterfly valves are widely used in working conditions with high temperature, low temperature, strong erosion, and have partially replaced globe valves, gate valves, and ball valves, so where are the main types of butterfly valves:
Belo Valve is a more than 15 years professional manufacturer for industrial valves, like butterfly valves( center line wafer butterfly valve, manual butterfly valve, lever driving butterfly valve, butterfly valve with worm gear box, lug type butterfly valve, soft seal butterfly valves, hard seal butterfly valves, flange butterfly valves, ductile cast iron butterfly valves, stainless steel butterfly valve), gate valves(including DINF4 gate valves, DINF5 gate valves, DIN3352 gate valves, rising stem gate valves, non rising stem gate valves, soft seal gate valves, hard seal gate valves, hydraulic gate valves, sluice valves), globe valves( DIN globe valves, bellows globe valves, electric globe valve), ball valves( welded ball valves, soft seal ball valves, stainless steel ball valves, WCB ball valves, ductile cast iron ball valves, API ball valves), check valves( wafer type check valves, swing check valves, rubber disc check valves, ball type check valve, foot valve/bottom valve), fire protection valves( grooved butterfly valves, grooved gate valves, grooved strainers, grooved check valves), hydraulic control valves,etc.
1. According to driving methods, butterfly valves can be divided into
2. According to structure style, butterfly valves can be divided into:
2.1. center seal butterfly valve
2.2. single eccentric seal butterfly valve
2.3. double eccentric seal butterfly valve
2.4. triple eccentric seal butterfly valve
3. according to the sealing material, butterfly valves can be divided into:
3.1. soft seal butterfly valve
3.1.1. the sealing pair of soft seal butterfly valve is composed of non metallic soft material to non-metallic soft material.
3.1.2. the sealing pair of soft seal butterfly valve is composed of metal hard material and non metal soft material.
3.2. metal hard seal butterfly valve:
The sealing pair of metal hard seal butterfly valve is composed of metal hard material to metal hard material.
4. According to sealing types, butterfly valves can be divided into:
4.1. forced sealing butterfly valve
4.1.1. resilient sealing butterfly valve: the sealing load pressure is generated by the resilience of the valve seat or valve plate when the valve plate squeezes the valve seat when the butterfly valve is closing.
4.1.2. external torque seal butterfly valve: the seal load pressure is generated by the torque applied to the valve shaft.
4.2. pressurized seal butterfly valve:
the sealing load pressure is generated by pressurized the resilient sealing element on the valve seat or valve plate.
4.3. automatic sealing butterfly valve:
the sealing load pressure is generated automatically by the medium pressure.
5. According to working pressure, butterfly valves can be divided into:
5.1. Vacuum butterfly valve:
vacuum butterfly valve refers to a butterfly valve whose working pressure is lower than the standard stack atmospheric pressure.
5.2. low pressure butterfly valve:
Low pressure butterfly valve refers to the butterfly valve with nominal pressure PN＜1.6Mpa。
5.3. medium pressure butterfly valve(also called middle pressure butterfly valve):
medium pressure butterfly valve refers to a butterfly valve whose nominal pressure PN2.5-6.4Mpa.
5.4. High pressure butterfly valve:
high pressure butterfly valve refers to a butterfly valve whose nominal pressure is PN 10.0-80.0Mpa.
5.5. super high pressure butterfly valve:
super high pressure butterfly valve refers to a butterfly valve whose nominal pressure PN＞100Mpa。
6. According to working temperature, butterfly valve can be divided into:
6.1. high temperature butterfly valve:
high temperature butterfly valve refers to a butterfly valve whose working temperature T＞450℃。
6.2. medium temperature butterfly valve(also called middle temperature butterfly valve):
medium temperature butterfly valve refers to a butterfly valve whose working temperature is 120℃＜T＜450℃。
6.3. normal temperature butterfly valve:
normal temperature butterfly valve refers to a butterfly valve whose working temperature is -40℃＜T＜120℃。
6.4. low temperature butterfly valve:
low temperature butterfly valve refers to a butterfly valve whose working temperature -100℃＜T＜-40℃。
6.5. super low temperature butterfly valve:
super low temperature butterfly valve refers to a butterfly valve whose working temperature T＜-100℃。
7. according to connection types, butterfly valves can be divided into:
7.1. wafer type butterfly valve
The disc of the wafer type butterfly valve is installed in the diameter direction of the pipeline. The wafer butterfly valve is in fully opened state.
The wafer type butterfly valve has a simple structure, small size, and light weight. Butterfly valve has two types of sealing: resilient sealing and metal hard sealing; for resilient sealing butterfly valve, the sealing ring can be inlaid on the valve body or attached to the periphery of the disc.
7.2. flange butterfly valve
The flange butterfly valve is a vertical plate structure, and the valve stem is an integral metal hard seal, the valve sealing ring is composite structure of flexible graphite plate and stainless steel plate, installed on the valve body, the sealing surface of the butterfly plate is welded stainless steel. The sealing ring of the soft seal butterfly valve is made of nitrile rubber(NBR in short) and is installed on the butterfly plate.
7.3. Lug type butterfly valve(also called wafer lug type butterfly valve)
The disc of the wafer lug butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical channel of the butterfly valve body, the disc shaped butterfly plate rotates around the axis, and the rotation angle is between 0°-90°。 when the disc rotates to 90°, the lug butterfly valve fully open.
The wafer lug type butterfly valve can be driven by manual, worm gear, pneumatic or electric, and the connection method can be selected from flange connect or wafer type connect. The structure of lug butterfly valve have center line, single eccentric, double eccentric, and triple eccentric. The sealing structure of lug butterfly valve have soft sealing structure and metal hard sealing structure. The pressure range of lug butterfly valve can go from PN0.1Mpa to PN10.0Mpa, its nominal diameter can go from DN40mm to DN2000mm. The material options for wafer lug type butterfly valve can be cast steel and stainless steel. Due to the wide application range of butterfly valves, in different conditions, the same valve should have different configurations.
7.4. welded butterfly valve
Welded butterfly valve is one kind of non sealed butterfly valve, which is widely used in pipelines with medium temperature ≤300℃ and nominal pressure 0.1Mpa, in the production process of building material, metallurgy, mining, electric power,etc, to connect, open and close or adjust the amount of the medium.
How butterfly valve works and where to use:
The butterfly valve is usually less than 90°from fully open to fully closed. The butterfly valve and the butterfly stem have no self-locking ability. In order to locate the butterfly plate, a worm gear reducer should be installed on the valve stem. The use of worm gear reducer can not only make the butterfly plate have self-locking ability, so that the butterfly plate can stop at any position, but also improve the operation performance of the valve.
The characteristics of industrial specific butterfly valves: high temperature resistance, high applicable pressure range, large valve nominal diameter, valve body made of carbon steel, sealing ring of valve plate is using metal ring instead of rubber ring. Large high temperature butterfly valve is welded with steel plates, which is mainly used for flue air duct and gas pipeline of high temperature medium.
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