The installation and maintenance of butterfly valves should pay attention to the following matters:
During installation, the valve disc should be stopped in the closed position.
2. The opening position should be determined according to the rotation angle of the butterfly plate.
3. For butterfly valves with bypass valves, the bypass valve should be opened before opening.
4. Installation should be carried out according to the manufacturer's installation instructions. For heavy butterfly valves, a solid foundation should be set up.
1、 The structural feature of this type of butterfly valve is that the valve stem axis, butterfly plate center, and body center are in the same position. Simple structure and convenient manufacturing. The common rubber lined butterfly valve belongs to this category. The disadvantage is that the butterfly plate and valve seat are always in a squeezed, scraped state, with large resistance distance and wear Quick.
2、 The single eccentric butterfly valve is designed to solve the squeezing problem between the butterfly plate and the valve seat of the concentric butterfly valve, resulting in the emergence of a single eccentric butterfly valve. Its structural feature is that the valve stem axis deviates from the center of the butterfly plate, so that the upper and lower ends of the butterfly plate no longer become the rotating axis, dispersing, and reducing the interference between the upper and lower ends of the butterfly plate and the valve seat Degree compression.
3、 The double eccentric butterfly valve, which is further improved and formed on the basis of the single eccentric butterfly valve, is currently the most widely used double eccentric butterfly valve. Its structural feature is that the axis of the valve stem deviates from both the center of the butterfly plate and the center of the body. The effect of double eccentricity enables the butterfly plate to quickly detach after the valve is opened
The valve seat greatly eliminates unnecessary excessive squeezing and scraping between the butterfly plate and the valve seat, reduces the opening resistance distance, reduces wear, and improves the service life of the valve seat.
4、 Three eccentric butterfly valves must be resistant to high temperatures, must use hard seals, but have a large leakage rate; To achieve zero leakage, a soft seal must be used, but it is not resistant to high temperatures. In order to overcome the contradiction of double eccentric butterfly valves, a third eccentricity was carried out on the butterfly valve.
Butterfly valve is a type of valve that uses a circular butterfly plate as the opening and closing element and rotates with the valve stem to open, close, and regulate the fluid channel. Butterfly valves not only have simple structure, small volume, light weight, low material consumption, small installation size, but also have small driving torque, easy and fast operation, and are also equipped with both.
Butterfly valves have excellent flow regulation function and sealing characteristics, and are the dominant valve form in the fields of large, medium, and low pressure applications.
With the application of anti-corrosion synthetic rubber and polytetrafluoroethylene, the performance of butterfly valves has been improved and can meet different operating conditions. In the past decade, metal sealed butterfly valves have developed rapidly, and with the use of high-temperature, low-temperature, strong corrosion, strong erosion resistance, and high-strength alloy materials in butterfly valves
The application of metal sealed butterfly valves has made them widely used under operating conditions such as high temperature, low temperature, and strong erosion, and partially replaced globe valves, gate valves, and ball valves.
Structural features: Butterfly valves have the characteristics of simple structure, small volume, light weight, low material consumption, small installation size, fast switching, 90 ° reciprocating rotation, and small driving torque. They are used to cut off, connect, and regulate the medium in pipelines, and have good fluid control characteristics and closing sealing Performance.
Nominal pressure or pressure level: PN1.0-4.0MPa, ANSI Class 150-300LB, JIS10-20K
Nominal diameter or diameter: DN40~2000
Connection method: flange connection, clamp connection, butt welding connection, and lug clamp connection
Applicable temperature: -196 ℃~700 ℃
Drive mode: manual, worm gear transmission, pneumatic, electric, hydraulic, gas-liquid linkage, electro-hydraulic linkage
Valve body materials: HT200, WCB, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, CF8 (304), CF3 (304L), CF8M (316), CF3M (316L), Ti.
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NO.139,Xianghe Road,Fangbu Industrial Zone,Tonglu,Hangzhou,China
