Chinese Association of Idaho State University (CAISU)
Butterfly valve features and methods of use
A butterfly valve is a valve in which the closing member (valve or disc) is a disc that rotates around the valve shaft to open and close and is used primarily for pipe cutting and throttling. The butterfly valve opening and closing member is a disc disc that rotates around its own axis in the valve body for the purpose of opening and closing or adjusting. From fully open to fully closed, the butterfly valve is usually less than 90 °. Butterfly valves and stems do not have self - locking capability. A worm gear reducer is added to the stem to position the disc. The use of worm gear reducer not only makes the disc self-locking, but also can stop the disc at any position and improve the operating performance of the valve.
Industrial special center line butterfly valve is characterized by high temperature resistance, suitable pressure range is also high, the valve nominal diameter is large, the valve body is made of carbon steel, the valve plate seal ring is made of metal ring rather than rubber ring. Large high temperature butterfly valve is manufactured by welding steel plate, which is mainly used for flue and gas pipeline of high temperature medium.
The advantages of butterfly valve are as follows:
1. Easy opening and closing, labor saving, low fluid resistance, frequent operation.
2. Simple structure, small size and light weight.
3, can transport mud, the least amount of liquid accumulated in the tube mouth.
4. Good sealing can be achieved under low pressure.
5. Good adjustment performance.
The disadvantages of butterfly valve are as follows:
1. Small working pressure and temperature range.
2. Poor sealing.
Butterfly valve installation and maintenance should pay attention to the following matters:
1. When installing, the disc should stop in the closed position.
2. The opening position shall be determined according to the rotation Angle of the disc.
3. Butterfly valve with bypass valve, open the bypass valve before opening.
4. The installation shall follow the manufacturer's installation instructions.