Operation or positioning of ball, butterfly and plug valves, ventilation dampers and automatic doors. Uses also include movement and positioning of components during manufacture – in fact anything that needs to be turned through 90° or less, automatically or by remote control.
- Single moving part
- Simplest and most reliable mechanism for quarter-turn rotary actuation.
- Close couple control modules
- Fail-safe spring returns, limit switches, positioners and solenoid valves all close couple to the actuators.
- No cranks or gearing
- No power loss or backlash – allows accurate positioning.
- Durable corrosion resistant finish
- Long maintenance-free life
- Up to 4 million operations guaranteed.
- Compact – space saving – efficient
- Best torque/size package available, fast operating speeds, best air consumption, proven design.
- Millions of units put into trouble free service all over the world.
- Choice of male or female output drive square – easy to interface to application
- Unique serial number for identification and traceability
EHD 1/4 Turn Acutators:
- Moves to and holds any position between 0° and 90° in response to control signal (4-20mA standard, split range available).
- Integral with standard actuator – no add-on modules. Excellent sensitivity, linearity, accuracy and stability. Available with fail-safe and double-acting actuators. Adjustable range, zero and dead band.
- Economical simple installation – only one connector block. Suitable for oscillating and unstable loads.
An electronic circuit and a feedback potentiometer are fitted inside the standard actuator control box. The circuit is a high stability linear comparator, which switches the actuator pump and solenoid valves via solid state mains switches in response to the difference between the actual position measured by the potentiometer and the intended position given by the 4-20mA signal. Limit switches prevent the actuator driving against its own endstop, whatever the signal may be.
The positioner mains switches are optically isolated from the low voltage DC control circuit, which is electrically isolated from the rest of the actuator.
The feedback potentiometer is a conductive plastic servo- type unit driven by a backlash-free drive. The positioner circuit is mounted inside an insulating polymer box for safety; it is fitted with screwdriver adjustable potentiometers to allow customer turning of zero, gain and dead band width.
The efficient design of the Kinetrol EHD valve actuator allows a high start frequency to be achieved, without overheating. The positioner is available on fail-safe spring-return and double-acting units, and gives accurate, linear low hysteresis performance with excellent thermal stability. The intrinsic stiffness of the hydraulic system together with the backlash-free design of the Kinetrol vane actuator makes this positioner very tolerant of varying or unstable loads (eg . butterfly valves). The complete absence of separately mounted enclosures makes installation neat, simple and economical – all external connections for power, signal and limit switches are made to the normal connector block in the control box.