Butterfly valve installation and maintenance should pay attention to the following matters
Number of clicks：26502018-09-21 14:03:21
Butterfly valve installation and maintenance should pay attention to the following matters:
1. when installing, the disc must be in the closed position.
2. the opening position should be determined according to the rotation angle of the butterfly plate.
3. butterfly valve with bypass valve should open bypass valve before opening.
4. should be installed according to the manufacturer's installation instructions. The butterfly valve with large weight should have a solid foundation.
1. Concentric butterfly valve The structural characteristics of the butterfly valve are that the shaft center of the stem, the center of the butterfly plate and the center of the body are in the same position. The structure is simple and the manufacture is convenient. Common rubber lined butterfly valve belongs to this category. The disadvantage is that the butterfly plate and valve seat are always in extrusion, scratch, resistance distance, wear.
Fast.
2. In order to solve the squeezing problem between butterfly plate and seat of concentric butterfly valve, a single eccentric butterfly valve is produced. Its structural feature is that the shaft center of the stem deviates from the center of the butterfly plate, so that the lower and lower ends of the butterfly plate no longer become the center of rotation, dispersing and reducing the passing of the lower and lower ends of the butterfly plate and the seat.
Degree extrusion.
3. The double-eccentric butterfly valve is the most widely used double-eccentric butterfly valve, which is further improved on the basis of Single-eccentric butterfly valve. Its structural characteristics are that the axis of the stem deviates from the center of the butterfly plate and also deviates from the center of the body. Double eccentric effect enables the butterfly plate to be detached immediately after the valve is opened.
The valve seat greatly eliminates the unnecessary excessive extrusion and scraping between the butterfly plate and the valve seat, reduces the opening resistance, reduces the wear and tear, and improves the service life of the valve seat.
4. Tri-eccentric butterfly valve must be high temperature resistant, must use hard seal, but large leakage; to zero leakage, must use soft seal, but not high temperature resistant. In order to overcome the contradiction between double eccentric butterfly valve and butterfly valve, it has made third eccentricities.
Butterfly valve is a kind of valve which uses circular butterfly plate as opening and closing piece and rotates with the stem to open, close and adjust the flow passage. Butterfly valve not only has simple structure, small volume, light weight, low material consumption, small installation size, but also small driving torque, simple and rapid operation, and also has.
The butterfly valve is the dominant type of valve in the application of large, medium and low pressure.
With the application of anti-corrosion synthetic rubber and polytetrafluoroethylene, the performance of butterfly valve can be improved and meet different working conditions. In recent ten years, metal-sealed butterfly valves have developed rapidly. With the development of high temperature resistance, low temperature resistance, strong corrosion resistance, strong erosion resistance, high strength alloy materials in butterfly valves.
The metal seal butterfly valve has been widely used in high temperature, low temperature, strong erosion and other working conditions, and partially replaced the globe valve, gate valve and ball valve.
Structural Features: Butterfly Valve has the advantages of simple structure, small volume, light weight, low material consumption, small installation size, quick switch, 90 degree reciprocating rotation, small driving torque and so on. It is used to cut off, switch on and adjust the medium in the pipeline. It has good fluid control characteristics and close seal.
Performance.
Nominal pressure or pressure level: PN1.0-4.0MPa, ANSI CLASS 150-300LB, JIS10-20K
Nominal diameter or caliber: DN40 ~ 2000
Connection mode: flange connection, clip pair connection, butt welding connection and lug coupling.
Applicable temperature: -196 C ~ 700 C
Driving mode: manual, worm gear drive, pneumatic, electric, hydraulic, pneumatic hydraulic linkage, electro-hydraulic linkage.
Body materials: HT200, WCB, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, CF8 (304), CF3 (304L), CF8M (316), CF3M (316L), Ti.
