Pneumatic actuators
Overview
Spirax Sarco pneumatic actuators provide linear valve actuation for control duties where compressed air remains the preferred power source for responsiveness, fail-safe action and straightforward integration into established plant control schemes. The PN9000, PN5700 and PN6700 diaphragm ranges, together with TN2000 cylinder actuators, cover different thrust and differential pressure requirements so the actuator can be matched to the installed valve and the real process load. Mechanical travel indication helps operators verify stroke position visually, while the actuator geometry supports stable valve movement and good linearity across the working range. Pneumatic actuation remains a practical choice where users want fast response, simple fail positioning and compatibility with smart positioners or existing instrument air infrastructure rather than a fully electric package. These actuators are commonly paired with SPIRA-TROL, QL and other Spirax Sarco two-port and three-port control valves, making this route useful when the project calls for a complete air-powered control valve assembly rather than an actuator in isolation.
Related pneumatic-package routes
Pneumatic actuators are usually selected as part of a larger valve package. Match them with steam control valves when the main issue is the modulating assembly itself, and use valve positioners where tighter signal tracking or diagnostics are needed.
If the plant is reconsidering whether air power is necessary at all, compare electric actuators.
Continue your pneumatic actuation selection
Pneumatic actuator selection affects response, fail action, control stability and how well the final valve package fits the existing plant air infrastructure.
See the wider control package context
Return to the wider control systems range when actuator choice is only one part of a larger project involving valve bodies, pressure control or complete control loops.
Pair the actuator with the right valve
Use the control valve range when the next step is matching actuator thrust, fail action and valve trim to the installed process duty.
Complete the pneumatic control package
Review positioners and controllers when the pneumatic package also needs feedback, diagnostics or tighter modulation under changing differential pressure.