Valves can be fitted with a pneumatic actuator that opens or closes the valve using air pressure.
Actuators consist of a housing in which a cylinder is placed. This cylinder is pressed one side by means of air pressure, so that the shaft of the actuator turns 90 °.
There are two types of actuators: double acting and single acting actuators. The single acting is pneumatically driven in one direction, the reverse direction of rotation is provided by a spring return. The single acting actuators are operated with a 3/2 control valve.
The double acting actuators consist of 2 internal air cylinders, each rotational direction being driven by one of the two cylinders. Thus, for both directions of rotation, air is required which is operated with a 5/2 control valve.
Actuators can be mounted on standard 2-way ball valves and butterfly valves. The valves with actuators are widely used as flow valves, waste water valves and other water streams that need to be air-driven quickly and easily.
The 2-way ball valves are available in PVC from 25 to 90 mm, in brass from ½" to 2.5" and in stainless steel from 3/8" to 2.5".
The butterfly valves are available in standard PVC in a range of 63 to 250 mm, in cast iron with stainless steel sheet from 50 to 500 mm and in Composeal in a range from 50 to 315 mm.