Valves are opened and closed by a reduction gear that transmits force to a drive shaft that is connected to the valve's stem. Positional control for opening and closing the valve is achieved through a limit switch. A positioning cam pushes the limit switch roller to cut off the power supply.
Advantages
1) Easy installation. Does not require pipe arrangement, which is necessary with a pneumatic actuator.
2) Ability to be controlled by an electrical circuit allows for easy sequential programming.
3) High output power can be obtained by a simple change in the reduction gear ratio.
4) Water hammer* can be eliminated or minimized because the actuating speed is lower than that of a solenoid valve.
5) Appropriate for remote-controlled operation.
Disadvantages
1) Not suitable for a valve that requires frequent actuation as it causes the motor coil temperature to increase significantly, causing the motor's fail safe mechanism to stop it.
2) Comparatively expensive in areas where an explosion-proof actuator is required by law.
3) Environmental and antiseismic considerations are required for a flow control valve actuator because electronic parts are used.
4) Actuating time depends on the motor or gear reduction ratio and is not readily changeable, unlike pneumatic actuators, which allows the actuating time to be easily changed as desired with the use of attachments.
5) A backup power unit is required for use in case of power interruption.
∗Water hammer is a pressure surge that occurs in the pipeline when a valve, is suddenly closed at one end of the pipeline system, forcing the fluid in motion to suddenly stop or change direction.
It occurs when the kinetic energy of the fluid in motion is converted into pressure energy.
High-speed On-Off Type
For ball valves
Low-speed On-Off Type
Floating control
For ball and butterfly valves
Proportional control
Analog-digital control type
For ball and butterfly valves
A visible travel indicator is included in the standard specifications.
An easy-to-operate type manual handle is included in the standard specifications.
Interlock switch is ON when the
manual handle is pushed in
(Automatic mode) Power on
(Power return)
Interlock switch is OFF when the manual handle is pulled up
(Manual mode) Power Off
Modular unit
A variety of options are available
Common parts and flexible modification options are available.
1)Limit switches
2)Potentiometers
3)Power supplies for different countries' voltages
• 100 / 200V  AC  (Standard)
• 110 / 220V  AC  (Optional)
• 115 / 230V  AC  (Optional)
• 120 / 240V  AC  (Optional)
4)External terminal box
5)Optional boards (Dedicated boards for the EXS Series)
• Board with terminal block (Standard)
• Relay type board (Optional)
• Speed controller
• R / I converter board (Optional)