Butterfly valves are commonly used in water systems. The valves are small and cost-effective, and they have become commonly used in pipelines. The main products of butterfly valve are clamped soft seal butterfly valve and flange butterfly valve. There are fewer types of butterfly valves than gate valves, but there are great differences according to the working conditions.
Butterfly valves are mainly divided into central type and eccentric type according to the structure, among which eccentric type is divided into eccentric type, double eccentric type and triple eccentric type.
The working principle of butterfly valve is as follows.
1、Principle of butterfly valve
Butterfly valve is a structure in which the valve plate rotates along the center line, and the volume of the valve plate is small. If the handle or worm wheel is rotated 90 degrees so that the valve is parallel to the medium flow, the valve will open. Therefore, butterfly valve has the characteristics of simple structure, small volume, light weight, small installation size, easy operation and fast opening and closing. There are also the characteristics of sealing and flow regulation. However, due to the high resistance of the valve, the medium pressure has a great influence on the opening and closing of the valve, so it is not suitable for high pressure environment.
2, butterfly valve in the performance of the advantages are mainly focused on small size, simple structure, open and close fast. Disadvantages are also obvious. The pipeline flow medium pressure loss is large, and it cannot be opened and closed in high pressure environment.
3、Different structure of butterfly valve
Centerline butterfly valve, single eccentric butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve have improved sealing performance and service life in turn, but the difficulties and costs of insufficient structure increase. If there are no special working conditions, it is often necessary to choose a more economical and suitable butterfly valve.
Butterfly valve troubleshooting
Methods for immediate solution in case of butterfly valve failure.
1、The leakage at both ends of the butterfly valve is caused by the seal on both sides. Uneven or uncompressed pressure force on the pipe flange. The seal can be replaced and the flange bolts can be compressed evenly.
2, butterfly valve valve leakage is caused by the butterfly valve plate, there is debris inside the seal. Butterfly valve and seal position error or uneven compression of the exit flange bolts. Pressure test deviation does not meet the requirements. Remove impurities, including valve steel. Adjust turbine or electric actuator, restrict screw to achieve the correct position of valve closing. Pressure test deviation does not meet the requirements. We have to rotate according to the deviation of the arrow.
