Cast iron butterfly valve

Author:butterfly valve     Published time:2019-01-31 09:38     Reading times:276    

Cast iron butterfly valve introduction:

The cast iron butterfly valve, also known as the flap valve, is a simple regulating valve and can also be used for switching control of low pressure pipeline media. High temperature resistance, high pressure range, large valve nominal diameter, valve body made of cast iron

Cast iron butterfly valve features:

The relationship between the opening and flow of a cast iron butterfly valve varies substantially linearly. If it is used to control the flow, its flow characteristics are closely related to the flow resistance of the piping. For example, the diameters and forms of the two pipe installation valves are all the same, and the pipe loss coefficient is different, and the flow difference of the valve is also large.

If the valve is in a state of large throttle, the back of the valve plate is prone to cavitation and may damage the valve. Generally, it is used outside of 15°.

When the cast iron butterfly valve is at the middle opening degree, the shape of the opening formed by the valve body and the front end of the disc is centered on the valve shaft, and the two sides are formed to complete different states. The front end of the butterfly plate moves in the direction of the water and the opposite side flows in the opposite direction. Therefore, the one side valve body and the valve plate form a nozzle-like opening, and the other side is similar to the orifice-shaped opening, the nozzle side has a much faster flow rate than the throttle side, and the negative pressure is generated under the throttle side valve. Rubber seals tend to fall off.

The operating torque of cast iron butterfly valve varies depending on the opening degree and the direction of opening and closing of the valve. Horizontal butterfly valves, especially large-diameter valves, cannot be ignored due to the water depth and the difference between the head and the head of the valve shaft. In addition, when the valve inlet side device is bent, a bias current is formed and the torque is increased. When the valve is in the middle opening, the operating mechanism needs to be self-locking due to the action of water flow torque.