||Spring Return, Double Acting
||Corrosion Protected Carbon Steel
||-40°C to +320°C
||Dry/Lubricated Air, Inert/Non-Corrosive Gases, Hydraulic
||Max 10 Bar-Pneumatic (145 PSI) Max 210 Bar-Hydraulic (3045 PSI)
Pneumatic Scotch Yoke Actuators are designed to operate in the harshest, most demanding industrial applications and environments where functionality and reliability are required throughout the complete cycle of valve automation. Predominantly used for larger sized Ball & Butterfly Valves the Scotch Yoke Actuator offers 90° quarter turn, on-off operation by converting linear movement to rotary action through the internal driving cylinder and scotch yoke mechanism with high start and end torque output up to 60,000NM. This, in turn, transmits power continuously and precisely to perform the operation of the Ball or Butterfly Vale. The ATHD Air Torque Scotch Yoke Actuator is a compact, lightweight and economical unit bringing reliability and low maintenance to industries where it is needed most and offering long, uninterrupted service. Available in both Spring Return & Double Acting units setup can be arranged in either the fail-safe open or closed positions, returning the actuator and valve position to the required safety location in the event of a power failure.
Double Acting Scotch Yoke Actuators:
In the example below, air supplied at port 2 is released into the chamber and forces the piston towards the central module of the scotch yoke actuator, in turn performing the counterclockwise rotation through the scotch yoke mechanism and opening of the connected valve. Exhaust air is exited through port 4. To perform the closing operation air is supplied through port 4 from the central module of the actuator. Forcing the piston to the end of the body chamber and clockwise rotation is achieved. Exhaust air is exited through port 2.
Spring Return Scotch Yoke Actuators:
For Spring Return Scotch Yoke Actuators, air supplied at port 2 is released into the chamber and forces the piston towards the central module of the actuator, this compresses the spring in the opposite chamber and performs the counterclockwise rotational movement, opening the valve. Exhaust air is exited through port 4. Depressurisation to port 2 through the use of an intentional or non-intentional action allows the spring to move the piston back towards the opposite end of the air chamber and immediately closes the valve. Exhaust air is exited through port 2.
Features And Benefits Of Pneumatic Scotch Yoke Actuators:
Pneumatic Scotch Yoke Actuators offer many features and benefits for the operational actuation of ball, butterfly and plug valves.
- A compact, lightweight, economical and reliable design provides long-lasting effective service.
- Higher breakout torque from zero position makes this actuator the perfect solution for soft seated ball and butterfly valves where 75% of the torque is generated by the seat.
- Increased torque for spring return position.
- Fail safe open or close setup available.
- Emergency manual override features including jack screw, hand pump and gear operation.