Installation instructions of butterfly valve

The relationship between the opening of the butterfly valve and the flow rate basically changes linearly. If it is used to control flow, its flow characteristics are also closely related to the flow resistance of the piping. If two pipelines are installed with the same valve diameter and form, but the pipeline loss coefficient is different, the valve flow rate will be very different.
If the valve is in a state with a large throttle range, the back of the valve plate is prone to cavitation, which may damage the valve. Generally, it is used outside 15 degrees.
When the butterfly valve is in the middle opening degree, the opening shape formed by the valve body and the front end of the butterfly plate is centered on the hair shaft, and the two sides form completely different states. move. Therefore, one side of the valve body and the valve plate form a nozzle-like opening, and the nozzle side has a much faster flow rate than the shutoff side. Negative pressure will be generated under the throttle side valve, and rubber seals will often fall off.
The operating torque of the butterfly valve has different values due to the different opening and closing directions of the valve. The horizontal butterfly valve, especially the large-diameter butterfly valve, due to the water depth, the torque produced by the difference between the upper and lower water levels of the valve shaft cannot be ignored.
In addition, when the elbow is installed on the inlet side of the valve, a bias current is formed and the torque will increase. When the valve is in the middle opening, the operating mechanism needs to be self-locking due to the action of the water flow torque.