How To Choose The Actuator Of The Sanitary Valve, Pneumatic Or Electric?

Introduction to pneumatic actuators and electric actuators

An actuator is a device that is responsible for moving or controlling a mechanism or system. The actuator for sanitary valves is operated by a power source, whether the operator turns the valve handle, the pneumatic cylinder or the electric motor. The two most common automatic actuators in the sanitary industry are electric and pneumatic actuators.

This article describes each actuator type and what to consider when specifying one of these for sanitary valve applications.

Pneumatic actuators

Pneumatic actuators are the most common type of automatic valve actuators we specify. Pneumatic actuators typically include pistons, cylinders and valves or ports. The piston is sealed to the cylinder wall by an O-ring or some other type of elastomeric seal. Some pneumatic actuators use a diaphragm instead of a piston. The diaphragm holds air in the upper portion of the chamber, allowing air pressure to force the diaphragm/piston down, moving the actuator rod, and actuating the valve.

Most pneumatic actuators will use a supply pressure of 40-120 PSI, with the most common pressure range being 60-80 PSI. Higher air pressures may be difficult to guarantee and maintain, while lower pressures will require very large pistons to produce the torque required to actuate the valve.

Pneumatic actuators usually contain an additional spring for fail-safe operation. In fail-safe actuators, when the air supply is interrupted, the spring drives the valve back to the desired position – open or closed. This is the source of the nomenclature for pneumatic actuators.

There are three types of pneumatic actuators:

  • Air turns on (normally closed)
  • Air turns off (normally open)
  • Air to air, or dual action

The double acting actuator has no fail-safe spring and relies on a supply valve to pressurize and release the actuator and change the valve position.

Electric Actuator

Electric actuators use a power source – the most common is a 110 volt AC power source that drives the motor, produces torque and changes valve position. Electric actuators are commonly used in applications where air is not readily available. They are easy to interface and interface with existing control systems, especially in control or modulation applications.

However, electric actuators have some drawbacks. First, electric actuators are usually much slower than pneumatic actuators. Although pneumatic actuators may stall, the stalling of electric actuators can result in excessive current consumption and potentially dangerous conditions. Electric actuators are also generally more expensive than pneumatic actuators. Despite these limitations, it is worth noting that position feedback and valve control devices and wiring are generally simpler than pneumatic devices that require an interface for pneumatic and electrical energy supply.

Electric actuators are typically used for quarter turn valves, such as sanitary ball valves or butterfly valves. Pneumatic actuators are available for quarter-turn valves as well as linear valves such as sanitary diaphragms and stem/seat type valves.

So which actuators should you take for your hygienic fittings-valves system? As you can see, it depends on several different factors, but if you are looking for a cheap, easy to install and sturdy actuator, use pneumatics. They are available in a variety of different sizes and torque values ??depending on your application. If you don’t have a ready-to-use air supply or are looking for something that can be easily connected and installed, then choose electric. If you have further questions, please contact us immediately.