A linear actuator converts a power source into straight-line motion. All three actuator types — pneumatic, hydraulic, and electric — accomplish this goal, but the mechanism behind each one produces a different set of tradeoffs for machine design, operating cost, and long-term reliability.
Electric actuators use a motor to turn a screw or drive a belt, hydraulic actuators use pressurized fluid to move a piston, and pneumatic actuators use compressed air to move a piston. The power source determines the actuator's force output, speed, precision, and maintenance profile, and it is usually the first decision an engineer makes when specifying a linear actuator.
When Should You Choose Pneumatic Over Electric or Hydraulic?
Pneumatic actuators work best where compressed air is already available, where the application needs high cycle speeds at moderate force, or where washdown, temperature extremes, or sanitary requirements rule out the alternatives. Air compressors already run in most industrial facilities, so a pneumatic actuator has ready access to its power source without added electrical or fluid infrastructure.
Pneumatic actuators cost less upfront than electric or hydraulic equivalents and involve fewer components to maintain. Because they use no motor and no hazardous fluid, they meet mechanical safety and food-grade requirements more easily than the alternatives, and they hold up in extreme heat, cold, and washdown environments where hydraulic fluid viscosity and electric motor housings become liabilities.
Pneumatic actuators do have a ceiling, though. Standard shop air limits the force a pneumatic cylinder can generate to 85-100 psi, and because air is compressible, pressure consistency can vary for applications with extremely tight tolerances.
What Factors Should Drive Your Actuator Power Source Decision?
Match the power source to the application using the checklist below.
- Force required. If the load needs more force than standard shop air pressure can deliver, hydraulic is the likely fit. If the load falls within pneumatic force ranges, pneumatic or electric both remain options.
- Precision required. If tolerances are tight and the actuator needs programmable, repeatable motion, electric is the strongest fit. Pneumatic are the least precise because air is more 'flexible' than hydraulic fluid.
- Duty cycle and speed. High-cycle, continuous-duty applications generally favor pneumatic or electric actuators over hydraulic.
- Holding requirements. If the actuator must hold a load in place for an extended period without continuous power draw, hydraulic is built for that job.
- Environment. Washdown, extreme temperature, or sanitary environments favor pneumatic or electric actuators. Hydraulic fluid loses viscosity in cold conditions and introduces contamination risk in sanitary settings.
- Mobility. If the equipment cannot be tethered to a fixed air line or power source, hydraulic's self-contained design is the only option among the three.
- Available infrastructure. An existing compressed air system favors pneumatic. An existing high-voltage supply with no space constraints favors electric. Neither infrastructure favors hydraulic unless the equipment is mobile.
- Budget, both upfront and over the equipment's life. Pneumatic actuators generally cost the least upfront and to maintain. Electric actuators cost the most upfront but can cost less to operate over time in applications that need only a few actuators. Hydraulic actuators carry ongoing maintenance costs tied to their additional components.
How Can Branham Help You Choose the Right Actuator?
Branham manufactures or distributes pneumatic actuators across the ULTRIQ, ARTEC, OVLPRO, DURATRK, and PNEU-SA product families. Our engineering team helps you size and specify the right cylinder once pneumatic is the right power source for your application.
Talk to our team about your force, speed, precision, and environmental requirements before you commit to a design.
