The valve is connected in series in the pressure line (between the supply pump and the fluid outlet).
Opening the Valve
The valve seal is opened as the target value signal increases:
liftactual < lifttarget
Valve Position Reached
The lift position of the valve is monitored with an integrated three-point-controller. This compares the target value signal with the actual lift position and transmits the signals <open>, <close>, <stop> to the drive. Medium pressure (FM) that thereby acts on the surface of the valve seal has no affect on the positioning behaviour. Pressure fluctuations are not registered by the sensor and also not stabilised:
liftactual = lifttarget
Closing the Valve
The valve seal closes as the target value signal decreases:
liftactual > lifttarget
Lift-repeat Accuracy
In this example the use of an RMQ as precision mixer is elucidated. The yellow fluid is added to the blue fluid until the desired mixture ratio is achieved. Subsequently, the mixture can be bottled and the process repeated. Since the lift position of the valve is constantly monitored by a 3-Point regulator, extremely accurate metering quantities are ensured and consequently an excellent process accuracy.
Altering the Mixture Ratio
The greater the target value signal is, the greater the lift of the valve. Consequently, in this example the volume flow and therefore the mixture ratio of the medium can be very precisely influenced.
