Control torque characteristics of butterfly valve.

The characteristic curve of butterfly valve operating torque is high in the middle and low at both ends. The reason for this impromptu phenomenon is that when the butterfly valve is in the middle position, the flow body is obstructed by the butterfly plate and flows around the butterfly plate, which will form a swirling flow on both sides of the butterfly plate and form a first-class hydrodynamic torque on the solenoid valve butterfly plate of the solar water heater, which forces the butterfly plate to close.

With the opening or closing of the butterfly plate, the swirling effect of the flow body on both sides of the butterfly plate becomes smaller and smaller until the swirling flow disappears. At this time, the block of the butterfly plate is also smaller and smaller, thus forming a characteristic curve of high middle and low two ends. For the two position three-way solenoid valve, the operating torque of the manufacturer is greater than that of the manufacturer when the valve is open than that when the valve is closed. The reason is that the hydrodynamic torque caused by the flow body on the butterfly plate is in the direction of closing the valve.

The maximum operating torque of unsealed butterfly valve appears in the middle position, while the maximum operating torque of sealed butterfly valve appears when the valve is closed, which is due to the additional sealing torque.