Butterfly valve, also called flip valve, is a simple structure of the regulating valve, but also can be used for low pressure pipeline medium switch control mode of the valve. Butterfly valve refers to the closing part (disc or butterfly plate) for the disc, revolving around the valve shaft to achieve the opening and closing of a valve, the valve can be used to control air, water, steam, all kinds of corrosive media, mud, oil, liquid metal and radioactive media and other types of fluid flow. In the pipeline mainly plays the role of cutting and throttling. The opening and closing part of butterfly valve is a disc-shaped butterfly plate, rotating around its own axis in the valve body, so as to achieve the purpose of opening and closing or adjusting. The butterfly valve is used to control the flow of fluid, mainly plays a cutting and throttling role in the pipeline.
Butterfly valve is now developing fast, towards high temperature, high pressure, large diameter, high sealing, excellent regulating performance, long life direction, has partially replaced gate valve, globe valve and ball valve. Butterfly valve as a component used to realize pipeline system on and off and flow control, has been widely used in petroleum, chemical industry, metallurgy, hydropower and many other fields. In the known butterfly valve technology, the sealing form of sealing structure, sealing material for rubber, PTFE and so on. Due to the limitation of structural characteristics, it is not suitable for high temperature resistance, high pressure and corrosion resistance, wear resistance and other industries.
The existing butterfly valve is a more advanced three eccentric metal hard seal butterfly valve, the valve body and the seat for connected components, valve seat sealing surface layer surfacing welding temperature resistant, corrosion resistant alloy material. The multi-layer soft laminated sealing ring is fixed on the valve plate. Compared with the traditional butterfly valve, the butterfly valve has the advantages of high temperature resistance, light operation, no friction in opening and closing. When closing, the butterfly valve is compensated with the increase of the torque of the transmission mechanism, which improves the sealing performance of the butterfly valve and prolonging the service life.
1. simple structure, small volume, light weight.
2. Good sealing can be achieved under low pressure.
3. opening and closing convenient and rapid, labor saving, fluid resistance is small, can be often operated.
4. can transport mud, in the pipe mouth accumulation of less liquid.
5. good adjustment performance.
1. poor sealing
2. use pressure and working temperature range is small
According to the structure, the butterfly valve can be divided into center seal, single eccentric seal, double eccentric seal and three eccentric test butterfly valve. The center seal belongs to the earlier butterfly valve form; Single eccentric sealing butterfly valve compared with the center sealing type, the structure is more complex, the cost is slightly higher, the sealing performance is better, the service life is longer, the use of pressure is higher; Double eccentric sealing type and three eccentric butterfly valve compared with single eccentric type, in turn for more complex structure, high manufacturing cost, better sealing performance, longer service life, higher pressure.
The characteristics of the industrial butterfly valve can withstand high temperature, the applicable pressure range is higher, the nominal diameter of the valve is large, the valve body is made of carbon steel, the sealing ring of the valve plate is made of metal ring instead of rubber ring. Large high temperature butterfly valve is made of steel plate welding, mainly used in high temperature medium smoke duct and gas pipeline.
Pay attention to the following during installation and maintenance:
2. The opening position should be determined according to the rotation Angle of the butterfly plate
3. Butterfly valve with bypass valve should be opened before opening
4. should be installed according to the manufacturer's installation instructions, large weight butterfly valve, should set a firm foundation
