Stem diameter: The valve can not be assembled into electric valve for multiple rotary type. Therefore, if the maximum stem diameter of the electric butterfly valve is not passed through the valve stem of the valve, the inner diameter of the hollow output shaft of the electric device must be greater than that of the valve stem of the clear rod valve. For the local rotary valve and many rotary valve in the dark rod valve, although not to consider the valve stem diameter through the problem, but in the selection should also be sufficient to consider the stem diameter and keyway size, so that the assembly can work normally.
Operation Torque: The operation torque is the main parameter of selecting the valve electric device. The motion process of the electric butterfly valve can be controlled by the size of the stroke, torque or axial thrust. Because the operating characteristics and utilization of the valve electric device depend on the type of valve, the working specification of the device and the position of the valve in the pipeline or equipment, the valve electric butterfly valve device is the indispensable equipment to realize the valve program control, self-control and remote control. Therefore, the correct choice of the valve electric device, to prevent the overload phenomenon (working torque is higher than the control torque) is essential.
The output torque of the electric device shall be 1.2-1.5 times times the maximum torque of the valve operation.
Electric Butterfly valve Operation Thrust: The main structure of the valve electric device has two kinds: one is not to configure the thrust plate. The output torque is converted from the stem nut in the thrust disk to the output thrust and the direct output torque. The other is to configure the thrust disk.
Output shaft Rotation Number: The number of the output axis of the valve electric device is related to the nominal diameter of the valve, the pitch of the stem, the number of thread heads. h for the valve to open the height, according to M=hzs calculation (m for the electric device should meet the total number of rotation rings. s for STEM drive thread pitch, Z for STEM thread head number.