Electric valve electric device is used to operate the valve and the valve is connected to one of the devices. The device is driven by electricity, and its motion can be controlled by the size of stroke, torque or axial thrust.
The operating characteristics and utilization of the valve actuator depend on the type of valve, the working specification of the device and the position of the valve on the pipeline or equipment.
The correct selection basis of electric device
Operating torque: It is the most important parameter to select the valve electric device.
Operation Thrust: The main structure of the valve electric device has two kinds, one is not to configure the thrust disk, at this time the direct output torque; the other is configured with a thrust disk, at which point the output torque through the thrust of the stem nut to output thrust.
Output shaft rotation number: valve electric device output shaft rotation number of the valve with the nominal diameter, stem pitch, thread number of head, according to M=h/zs calculation.
Stem diameter: For many rotary type of the valve, if the electric device allows the maximum valve stem diameter can not be equipped with valve stem, it can not be assembled into electric valves.
Output speed: Valve opening and closing speed, easy to produce water hammer phenomenon
installation, connection mode: The installation of electric device has vertical installation, horizontal installation, landing installation, the connection is the thrust plate, valve stem through, the dark rod multiple slewing, no thrust plate, its main use in closed-circuit valves.
To judge the increase or decrease of the input current of the motor
To judge the heat of the motor itself
A thermostat is used for the overload protection of the motor running continuously or in operation.
To protect the motor from the thermal relay
Use fuse or overcurrent relay for short-circuit accident The correct choice and overload prevention are related, should arouse attention