English
Operates by forcing compressed air into a full-bore air cylinder. Inside the cylinder, a piston rod is housed. Air pressure from an external compressor is forced into the cylinder to create linear movement of the piston rod, either forward or backward. The piston rod is attached to a blade’s clevis or shaft. This assembly works in tandem to actuate the valve’s blade into a specified position.
Technical Specifications
• Double-acting air cylinder
• Designed with a magnetic piston to accommodate magnetic switches, for position indication.
• Oversized option for greater closing force.
• Double-stage option to accurately reach the middle position in three-way diverter valves.
• Cylinder construction options: Aluminum, epoxy-coated (for corrosive environments), 304 or 316L stainless steel
• High temperature modification: Cylinder constructed with fluoroelastomer seals
• Can be built to ATEX compliance
For limited space installations and/or greater closing force. A dual cylinder design can reduce a valve’s overall footprint by 30%.
Technical Specifications
• Compatible Vortex products: Roller Gate, Titan Slide Gate, Gravity Vee Diverter
• Size: Contact us for sizing options
• Simple design for easy maintenance.
• Other actuators require a manual override or alternative power sources to prepare for electrical loss. A pneumatic actuator’s solenoid valve can be programmed so that the gate/diverter will fail closed or remain idle in its current position.
• Metering options.
• Can be PLC-operated.
• Cannot be actuated in the case of air supply failure.
• Typically, additional accessories are needed in order to accurately hit intermediate positions. These add cost and complexity.
• Not practical for larger valves because of inefficient compressed air consumption.
Operates using an electric motor. Inside the housing, a lead screw is attached to the motor. Once the motor is started, the lead screw will begin to rotate. Also attached to the lead screw is a lead nut, which is threaded to move oppositely to the lead screw. The lead nut is attached to a blade’s clevis or shaft. Similar to a power drill, depending on the direction of actuation, the lead screw will spin one direction or the other. This creates linear movement and causes the valve’s blade to actuate into a specified position.
Options:
• Explosion-proof electric linear actuator
• Potentiometer: Provides continuous variable feedback signal directly proportional to the actuator’s stroke. This allows the actuator to be connected to control equipment, to provide positioning of the actuator stroke at any point – from full extension to full retraction.
• Can include encoders for total control of velocity, position, torque and applied force.
• In terms of noise, electric actuators are the quietest of the powered actuator types.
• No leakage of air or fluids, so environmental hazards are eliminated.
• Can be PLC-operated.
• Compressed air is not needed.
• More suitable for use in cold, outdoor climates. With pneumatic actuators, compressed air moisture can freeze in the air lines, causing actuation failure.
• In case of electrical loss, an electric actuator requires manual override or an alternative power source in order to fail closed.
• If left running continuously, the electric motor can overheat and wear on the reduction gear.
• The motors for electric actuators can be large, which creates installation difficulties.
• In terms of force, thrust and speed, the motor is non-adjustable. In order to improve or reduce actuator performance, the motor must be changed.
Hand Crank – For standard manual actuation.
Hand Wheel – For quicker manual actuation.
Chain Wheel – To manually actuate out-of-reach valves.
Rack & Pinion
Allows rapid actuation of especially large sized valves.
ACME-threaded rod
5:1 or 11.5:1 ratio with a rising action to adequately close through a column of material.
• Does not require a power source. This also makes them more reliable.
• Inexpensive.
• Because they are human-operated, it is easier to identify actuation issues.
• Not automated; requires a human operator for each actuation.
• Slower actuation, compared to powered actuator types.
• Intended for low-actuation applications.
Operates using hydraulic fluid, rather than compressed air. Inside the cylinder, a piston rod is housed. Hydraulic fluid from an external reservoir is forced into a full-bore cylinder to create linear movement of the piston rod, either forward or backward. The piston rod is attached to a blade’s clevis or shaft. This assembly works in tandem to actuate the valve’s blade into a specified position.
• Intended for high-force applications. A hydraulic actuator is capable of forces up to 25x greater than that of a double-acting air cylinder of equal size.
• Can hold constant force and torque without the pump supplying more hydraulic fluid or pressure.
• Can be PLC-operated.
• Will leak hydraulic fluid, which creates concern for cleanliness, environmental contamination and other safety issues.
• More systematic and complex, compared to other powered actuator types.
