Pneumatic vs. Electric Actuators: How to Select the Right Option

Power Source

The biggest difference between electric and pneumatic actuators is the driving force of their operation. 

Pneumatic actuators require an air supply of 60 to 125 PSI. The solenoid (pilot) valve is controlled by either an AC or DC voltage.

When no air supply is available, electric actuators are used.

Component Size

Double-acting pneumatic actuators are up to 70% smaller in size compared to electric actuators.

Speed

To open or close the valve, pneumatic actuators take 1⁄2 a second to 1 full second, depending on the model. Gemini’s electric actuators take approximately 6 seconds, while other manufacturers can take upwards of 25 seconds or more.

Temperature

Pneumatic actuators are suitable for a wide variety of ambient temperatures, and are rated to operate in temperatures between -20°F and 350°F. Electric actuators can be at risk of overheating in high temperature applications and are often rated between 40°F and 150°F. However, the temperature restrictions will vary depending on the product and the company’s guidelines for rating their products. 

Durability & Longevity

High quality rack & pinion style pneumatic actuators can cycle on or off up to 1,000,000 +/- times when used within specifications. Electric actuators have cycles of 250,000 +/- but are application dependent.

NEMA Ratings

The National Electrical Manufacturers Association (NEMA) sets guidelines for the use of actuators in specific environments, like hazardous areas or locations affected by water and debris. 

Pneumatic actuators are explosion proof, though care must be taken when paired with a flush mounted solenoid valve. Electric actuators are designed to the following most-common NEMA ratings:

• NEMA 4: Water-tight and intended for indoor or outdoor use. This rating sets a level of protection against dirt, water and ice. 

• NEMA 4X: Similar to NEMA 4, with an additional level of protection against corrosion.

• NEMA 6: Submersible, with design dependent on the specified conditions and time.  

• NEMA 7: Designed for indoor applications and certain hazardous environments. Capable of withstanding pressure from internal explosions.

Spring-Return

A safety feature for valve actuators is a spring-return or failsafe option. In the event of a power or signal failure, the spring-return sets the valve to the “safe” position determined by the operator. 

Spring-return failsafe options are widely available for pneumatic actuators. However, this feature is not as easily implemented with electric actuators. 

Cost

Pneumatic ball valves generally have a lower purchase price than electric ball valves. When used within specifications, they have a longer lifespan and may deliver the best overall value depending on your application.

• Air Supply of 60 to 125 PSI 

• Solenoid Valve Controlled By AC or DC Voltage

• Voltage of 120AC / 24DC / 12DC

• 2.66” x 3.41” x 3.63” (Double Acting)

• 2.86” x 8.11” x 3.63” (Spring Return)

• 7.70” x 6.45” x 4.75” 

• 1⁄2 a Second to 1 Second

• 6 Seconds

• -20° to 350° F

• -40° to 150° F

• 1,000,000 +/- When Used Within Specifications

• 250,000 +/- Application Dependent

• Widely Available

• Not Widely Available

• Oil & Gas

• Automotive

• Pharmaceutical

• Food & Beverage

• Power Processing

• Chemical Admixtures & Treatment

• Food Service Equipment

• Irrigation

• Vehicle Wash Systems

• Water Treatment Equipment

• Manufacturing Facilities