Pneumatic Rotary Valve Actuator Accessories
Position control, monitoring and feedback accessories for rotary pneumatic actuators
Air actuated valves require pneumatic rotary valve actuator accessories to control them and to feed back their position, typically to a control room or control panel, and there are many air actuator accessories available.
Basic levels of control of a pneumatic valve are provided by Namur solenoid valves that, whilst continuously having compressed air connected, controls the opening and closing of the valve electrically by energising and de-energising the solenoid valve coil. Confirmation that the air operated valve has reached the full open or full closed position requires a limitswitch box that typically contains cam operated internal switches operated by the pneumatic valve actuators pinion.
For proportional control of air actuated valves where fine flow control is required, a pneumatic actuator positioner is fitted that typically converts a 4-20mA input signal from a process controller into a pneumatic signal, that the positioner then uses to set the opening angle of the valve actuator proportionally to the input control signal.
Most pneumatic actuator accessories are available in different versions that allow them to be used in specific atmospheres, more commonly referred to as safe areas or hazardous areas. For hazardous area applications, valve actuator accessories must be tested and certified for either the Zone 1 which requires Exd explosion proof rate accessories, or Zone 0 requiring EExia or intrinsically safe accessories. Many are available either with the standard aluminium housings and optional stainless steel housings.
J+J stock and distribute the quality Power Genex range of air control, monitoring and feedback devices with switch boxes, positioners,volume boosters and air filter regulators being the more commonly supplied products.