Pneumatic actuators
Pneumatic actuators use pressurized air to generate mechanical force to operate the valves. They are the most widely used actuators in different industries delivering quick response to the process requirements. We provide our customers with a various range of high quality pneumatic actuators from well-known brands (e.g. AirTorque, Wirematic and Rotork) to assure an accurate and stable control, minimum maintenance and maximum service and support to end users.
These actuators are available in single acting for fail-safe requirement or double acting configuration. In single acting, the air load from the valve positioner drives the actuator in one side while the other side is controlled by the spring load. This type of configuration perfectly suit the process safety applications where fail-close (i.e. valve should be closed in loss of signal) or fail-open (i.e. valve should be opened in loss of signal) is a requirement.
In double acting configuration, the actuator is operated by air load on both sides. Double acting actuators can provide smooth and stable control in many applications. For instance, they are the best choice for fail in last position requirement, meaning the valve should be turned to its last position if the control signal is lost. We deliver pneumatic actuators that follow either Scotch yoke or rack and pinion principles.
Rack and pinion VS. Scotch yoke
In rack & pinion mechanism a circular gear (pinion) rotates by two gear bars (racks) due to the air pressure in the outer/inner chamber of the actuator. This results in a rotary motion of the actuator. While in the Scotch-yoke actuators rotary motion is achieved by linear motion of a slider/piston. The reciprocating part is coupled to the sliding yoke with a slot that engages a pin on a disk-shaped crank. The air pressure in the piston inserts a force to rotate the crank resulting in the actuator rotary motion.
Rack & pinion actuators are normally used for control purposes since they give a constant torque in all positions. However, Scotch yoke actuators gives better performance for On-Off valves/applications (e.g. ball and butterfly valves) due to higher torque output at the start and end of the valve stroke.
These actuators have housing and inner parts in anodized aluminium and stainless steel and other treatment on request for harsh environment. They offer highly safe operation in numbers of applications with different hazardous area classifications.
AT model, an Air Torque rack and pinion actuator, delivers high performance and reliable control, utilizing the latest available technology and materials.
AT series, fast & safe operating actuators with adjustable travel stops, uses the rack and pinion mechanism to produce a quarter turn movement. The operation is based on a pressure signal inserting a force on the balanced piston surface following by a conversion into a rotary motion through a pinion shaft.
These actuators are available in both spring return (SR) and double acting (DA) configurations suitable for various applications.
The RC200 model is a Rotork pneumatic actuator, giving high torque in end position. These actuators are light, very compact and have a robust design especially with manual override solution. Low stroke volume to reduce the amount of compressed air and low maintenance are other advantages of this type of actuator.
RC200 series features Scotch yoke principle in which the rotary motion is achieved by linear motion of a slider/piston. The reciprocating part is coupled to the sliding yoke with a slot that engages a pin on a disk-shaped crank. The air pressure in the piston insert a force to rotate the crank resulting in the actuator rotary motion.
They are available in both spring return and double acting configurations and suitable for both On/Off and regulating.
Wirematic rack & pinion type of actuators, offer a wide range torque to generate a quarter turn movement.
In rack & pinion mechanism a circular gear (pinion) rotates by two gear bars (racks) due to the air pressure in the outer/inner chamber of the actuator. This results in a rotary motion of the actuator.
These actuators can be configured as spring return (SR) or double acting (DA). The springs are placed inside the piston rack in an anodized aluminium casing resulting in a high quality compact design, suitable for rotary valves.
