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Motor actuated

Motor actuated

The automation of production equipment and processes with the aid of electronic regulation and control equipment requires interfaces between the electronic and fluidic control loops.

The valve described below for regulating the flow rate of liquids and gases represents such an interface. Fluids are mainly delivered and isolated by solenoid actuated on-off valves. However, the way they and manually actuated throttle valves operate does not meet certain flow requirements. Therefore, wherever exact adjustment to the actual requirement is needed, one of the wide range of motorised valves on offer is used. Depending on the application and accuracy required, it is possible to chose between an extremely wide variety of control element and drive design principles.

This is a rotary valve, with two oxide ceramic throttling discs which resist dirt and do not wear.

The maintenance free electrical servodrive consists of powerful reversible motors; with a choice between DC, synchronous and stepper designs to suit the type of control system available.

The backlash free gearing, which is positively connected to the drive shaft in order to rotate the control disc, guarantees a reproducible defined control characteristic. The limit - i.e. valve closed or fully open - is detected by two separate, floating microswitches. As a result of the low power consumption of between 1.5 and 5W, the electronic regulator can operate certain types of motor directly.

For controlling the motorised valve, various regulators and electronic components are offered, which in combination with the valve allow simple control through to complex regulation problems to be solved, e.g. flow and temperature regulation or electronic control cards like servo-amplifier or stepper motor controller.

Description of operation:

Control discs

One of these discs opens two opposite triangular flow apertures in the other continuously, over an angle of rotation of 90°. The matching geometry of the pair of disks achieves a virtually linear flow characteristic. The particular throttle cross section adopted is retained if the control voltage is switched off. Positive overlapping tight enough to prevent dripping is ensured in the closed position.