Pneumatic Actuated Valve

Pneumatic Actuated Valve Manufacturer in Germany

Pneumatic actuated valves use compressed air to automate valve opening, closing or positioning in industrial piping systems. Depending on the valve design, the actuator produces rotary or linear movement and can be configured for on off isolation or modulating control. Their fast response and ability to provide a defined fail position make pneumatic systems suitable for automated process lines and safety-related applications.

Air Operated Valve Automation:

A pneumatic actuator converts compressed air pressure into mechanical movement. Air enters one or more actuator chambers and acts against a piston or diaphragm, producing either rotary torque or linear thrust.

The actuator then transfers this force to the valve stem or shaft.

Pneumatic automation is used for:

Remote pipeline isolation
Emergency shutdown
Sequence control
Process flow regulation
Frequent cycling
Automated batching
Operation in inaccessible locations

Spring Return and Double Acting Actuators:

Spring Return Actuator

Uses air in one direction and spring force for return.
Moves to a preset fail open or fail closed position if air supply is lost.
Selected according to process safety requirements.

Double Acting Actuator

Uses compressed air for both opening and closing.
Suitable where higher torque and controlled movement are required.
Typically remains in its last position after air loss unless a separate fail-safe system is provided.

Quarter Turn and Linear Valve Configurations:

Pneumatic actuators can operate different valve motions.

Quarter Turn Valves

Ball, butterfly and plug valves normally require approximately 90° rotation.
Rack and pinion actuators provide compact quarter turn operation, while scotch yoke actuators can provide higher torque characteristics for larger valves and demanding pressure conditions.

Linear Valves

Globe, gate and knife gate valves require linear stem or gate movement.
Pneumatic diaphragm or piston cylinder actuators can generate the thrust required for these configurations.
Globe and control valve assemblies can also use pneumatic actuators for modulating service where intermediate positioning is required.

Air Supply and Torque Requirements:

Important sizing parameters include:

Valve breakaway torque
Running torque
Seating torque
Stem thrust
Maximum differential pressure
Available instrument-air pressure
Required safety factor
Opening and closing time
Cycle frequency
Fail safe spring requirement

Technical Specifications:

Parameter	Typical Specification
Valve Types	Ball, Butterfly, Gate, Globe, Plug, Knife Gate and Control Valve
Size Range	DN15–DN1200 depending on valve type
Pressure Rating	PN10–PN100; ASME Class 150–2500 depending on valve design
Actuator Types	Rack and Pinion, Scotch Yoke, Diaphragm, Pneumatic Piston
Actuation	Spring Return / Double Acting
Typical Air Supply	Approx. 4–8 bar
Motion	Quarter Turn or Linear
Fail Position	Fail Open, Fail Closed, Fail in Place for applicable configurations
Body Materials	Carbon Steel, Stainless Steel, Cast/Ductile Iron, Duplex, Super Duplex and special alloys
Seat Materials	PTFE, RPTFE, EPDM, NBR, FKM, PEEK or Metal depending on valve
End Connections	Flanged, Wafer, Lug, Butt Weld, Socket Weld, Threaded
Accessories	Solenoid Valve, Positioner, Limit Switch Box, AFR, Quick Exhaust Valve
Valve Testing	EN 12266-1 / API 598 or valve specific requirement
Actuator Protection	Weatherproof or hazardous area configurations according to selected actuator

Solenoid, Positioner and Limit Switch Options

Pneumatic actuator assemblies can incorporate accessories for control, air preparation and position monitoring.

Solenoid Valve

The solenoid valve directs compressed air to and from the actuator in response to an electrical command from a PLC, DCS or local control system.

Positioner

A positioner compares the required valve position with actual stem or shaft position and adjusts actuator air pressure accordingly.

Electro-pneumatic positioners commonly accept signals such as 4–20 mA for modulating applications.

Limit Switch Box

Limit switches provide electrical confirmation of valve open and closed positions for remote indication and interlocking.

Additional accessories can include:

Air filter regulator
Pressure gauge
Quick exhaust valve
Speed control valve
Position transmitter
Manual override

Fail Safe Position Selection:

The correct fail position depends on what must happen if instrument air or electrical control is lost.

Fail Closed: Valve closes on air loss to stop process flow in fuel, chemical feed or isolation service.
Fail Open: Valve opens on air loss where continued flow is needed, such as cooling or protective utility service.
Fail in Place: Valve remains near its last position using a double acting actuator with suitable air-lock controls.
Selection: Fail action should be based on process safety and hazard requirements.