Fast and precise control of large valves

Samson controls have introduced a new positioner package for exact valve positioning, with fast response times over the entire operating range, even for large control valves

For example, in most process control applications, larger valves are fitted with pneumatic actuators, which provide significant positioning forces.

In these situations the positioner is used to precisely position the valve by filling the actuator with the corresponding amount of air, or by venting air from the actuator.

The air output capacity required to achieve fast positioning in larger actuators (with diaphragm areas of 1400cm2 up to 2800cm2) is simply too much for normal positioners and so positioning accuracy can be compromised.

In these situations the positioner controls a volume booster which achieves a much higher air output capacity than the positioner.

Consequently this results in an overshoot on responding to small signal changes.

The new Samson positioner package, which consists of a positioner and a special hook-up of several volume boosters with different air output capacities, accomplishes this task.

Closing and opening times of less than two seconds can be achieved over the entire positioning range.

This package has already been used successfully for compressor bypass valves (anti-surge valves) as well as in petrochemical applications involving adsorption processes in moving-bed adsorbers.

Back to top