Valve electric device is one of the devices used to connect the valve and the valve. The device is driven by electric power, and the movement process of the device can be controlled by the size of the stroke, the torque and the axial thrust. Due to the valve electric device should have the work characteristics and utilization depends on the type of valve, the work of the device specifications and the position of the valve in the pipeline or equipment. Therefore, to grasp the correct choice of the valve electric device, to prevent overload (working torque higher than the
control torque) is a vital part of the.
The correct choice of valve electric device should be based on:
1.operating torque: operating torque is the most important parameter to select the valve electric device. The output torque of the electric
device should be 1.2~1.5 times of the maximum torque of the valve operation.
2.operation thrust: the structure of main valve electric device has two kinds, one is not configured thrust plate, this time directly to the output
torque; the other is equipped with thrust plate, this time the output torque of the stem nut through the thrust plate is converted to output thrust.
3.output shaft rotation number: valve electric actuator output shaft rotation the number of laps and the valve nominal diameter, stem pitch,
thread number, calculated according to M=H/ZS (in which M is the total number of rotating ring; the electric device should meet the H height,
the valve opening mm S to stem transmission; thread pitch, mm; Z for the stem thread number).
4.stem diameter: for multi swing type of valve, if the electric device allows the maximum stem diameter can not be through the valve stem, it can not be assembled into an electric valve. Therefore, the inner diameter of the hollow output shaft of the electric device must be larger than
the outer diameter of the valve stem. For the part of the rotary valve and multi turn valves in the dark bar valve, though not considered by the
stem diameter, but the selection should also take full account of stem diameter and keyway size, so that work can be assembled.
5.output speed: the valve opening and closing speed is fast, easy to produce water hammer phenomenon. Therefore, it should be based on
different conditions of use, choose the appropriate opening and closing speed.
6.installation, connection mode: the installation of the electric installation method has vertical installation, horizontal installation, installation of
A thrust disc valve stem through (the valve of the valve)
Dark rod rotary
No thrust disc valve stem is not passed
The use of electric equipment is very wide, is the realization of the valve control, automatic control and remote control of the indispensable equipment, which is mainly used in the closed valve. But can not ignore the special requirements of the valve electric device - must be able to limitthe torque or axial force. The connector is usually electric valve actuators with limited torque.
After the specification of the electric device is determined, the control torque is also determined. When the motor is running in a predetermined time, the motor will not be overloaded. In case of any of the following circumstances, the overload:
1.the power supply voltage is low, can not get the required torque, the motor stops rotating.
2.the torque limiting mechanism is incorrectly adjusted, which is greater than the stop torque, and the continuous generation of too large
torque, so that the motor stops rotating.