Electric devices are indispensable driving equipment for remote control, automatic control, and remote control of valves. The movement process of electric actuators can be controlled by the magnitude of stroke, torque, or axial thrust. Due to the working characteristics and utilization rate of valve electric devices, they depend on the type of valve, the operating specifications of the device, and the position of the valve on the pipeline or equipment.

电动装置一般由下列部分组成：

Electric devices generally consist of the following parts:

专用电动机，特点是过载能力强﹑起动转矩大﹑转动惯量小，短时﹑断续工作。

A specialized motor characterized by strong overload capacity, high starting torque, small moment of inertia, and short and intermittent operation.

减速机构，用以减低电动机的输出转速。

A reduction mechanism used to reduce the output speed of the motor.

行程控制机构，用以调节和准确控制阀门的启闭位置。

The stroke control mechanism is used to adjust and accurately control the opening and closing position of the valve.

转矩限制机构，用以调节转矩(或推力)并使之不超过预定值。

Torque limiting mechanism, used to adjust torque (or thrust) and ensure that it does not exceed a predetermined value.

手动﹑电动切换机构，进行手动或电动操作的联锁机构。

Manual or electric switching mechanism, an interlocking mechanism for manual or electric operation.

开度指示器，用以显示阀门在启闭过程中所处的位置。

Opening indicator, used to display the position of the valve during the opening and closing process.

一、根据阀门类型选择电动执行器

1、 Select electric actuators based on valve type

．角行程电动执行器（转角<360度）适用于蝶阀、球阀、旋塞阀等。

Angular stroke electric actuators (angle<360 degrees) are suitable for butterfly valves, ball valves, plug valves, etc.

电动执行器输出轴的转动小于一周，即小于360度，通常为90度就实现阀门的启闭过程控制。此类电动执行器根据安装接口方式的不同又分为直连式、底座曲柄式两种。

The rotation of the output shaft of the electric actuator is less than one cycle, which is less than 360 degrees, usually 90 degrees, to achieve valve opening and closing process control. This type of electric actuator can be divided into two types based on the different installation interface methods: direct connection type and base crank type.

直连式：是指电动执行器输出轴与阀杆直连安装的形式。

Direct connection type: refers to the form of direct connection installation between the output shaft of the electric actuator and the valve stem.

底座曲柄式：是指输出轴通过曲柄与阀杆连接的形式。

Base crank type: refers to the form in which the output shaft is connected to the valve stem through a crank.

多回转电动执行器（转角>360度）适用于闸阀、截止阀等。

Multi turn electric actuators (angle>360 degrees) are suitable for gate valves, globe valves, etc.

电动执行器输出轴的转动大于一周，即大于360度，一般需多圈才能实现阀门的启闭过程控制。

The rotation of the output shaft of the electric actuator is greater than one cycle, which is greater than 360 degrees. Generally, multiple cycles are required to achieve valve opening and closing process control.

二、根据生产工艺控制要求确定电动执行器的控制模式

2、 Determine the control mode of the electric actuator according to the production process control requirements

开关型（开环控制）

Switch type (open loop control)

开关型电动执行器一般实现对阀门的开或关控制，阀门要么处于全开位置，要么处于全关位置，此类阀门不需对介质流量进行精确控制。

Switch type electric actuators generally achieve open or close control of valves. The valves are either in the fully open or fully closed position, and this type of valve does not require precise control of medium flow.

特别值得一提的是开关型电动执行器因结构形式的不同还可分为分体结构和一体化结构。选型时必需对此做出说明，不然经常会发生在现场安装时与控制系统冲突等不匹配现像。

It is particularly worth mentioning that switch type electric actuators can be divided into split structure and integrated structure due to different structural forms. When selecting a model, it is necessary to explain this, otherwise mismatches such as conflicts with the control system during on-site installation may often occur.

分体结构（通常称为普通型）：控制单元与电动执行器分离，电动执行器不能单独实现对阀门的控制，必需外加控制单元才能实现控制，一般外部采用控制器或控制柜形式进行配套。 此结构的缺点是不便于系统整体安装，增加接线及安装费用，且容易出现故障，当故障发生时不便于诊断和维修，性价比不理想。

Split structure (usually referred to as ordinary type): The control unit is separated from the electric actuator, and the electric actuator cannot independently control the valve. It is necessary to add a control unit to achieve control. Generally, the external system is equipped with a controller or control cabinet. The disadvantage of this structure is that it is not convenient for the overall installation of the system, increases wiring and installation costs, and is prone to faults. When faults occur, it is not easy to diagnose and repair, and the cost-effectiveness is not ideal.

有了良工阀门代理上面的小总结，希望对广大客户有所帮助，如果有什么不理解的或者寻求帮助的请点击我们的网站：http://www.jnlgvf.com

With the summary above from Lianggong Valve Agency, I hope it can be helpful to our customers. If you have any questions or need help, please click on our website: http://www.jnlgvf.com