Scotch Yoke Pneumatic Actuator

Scotch Yoke Pneumatic Actuator

The single/double acting Scotch Yoke Pneumatic Actuator, is suitable for the operation of quarter turn valves (ball valves, butterfly valves and plug valves) for on-off and modulating heavy duty service. The actuator is made up of a waterproof scotch yoke mechanism transforming the linear movement of the pneumatic cylinder (on closing or opening) into the rotary movement, which is necessary for valve operation.

►Double acting or spring return compact design.
►Totally sealed weatherproof housing that provides complete protection for all moving parts.
►Housing is manufactured in carbon steel material without any cast/grey/ductile iron or aluminium parts.
►Scotch yoke mechanism available in both canted or symmetrical executions.
►Chromium plated guide bar to absorb transversel forces.
►Bushings are made of PTFE-filled steel bronze (other materials on application).
►Electroless nickel plated cylinder to minimise friction and prevent corrosion.
►Power module safety design allows replacement of the cylinder seals without any danger.
►Multiple certified lifting lugs ideally located to balance center of gravity for safe lifting.

Output torque：250000N.M
Mode of action： Single acting, double acting
Power Type： Pneumatic, hydraulic
Manual Type： Screw handwheel, gear, hydraulic manual
Fault location：FC, FO, FL
Ambient temperature: normal temperature, low temperature, high temperature
Accessories: solenoid valve, limit switch, electric positioner, retaining valve
Valve type: ball valve, butterfly valve and other rotary valve

Safety: ATEX, SIL 3 suitable, PED on request

The Scotch Yoke pneumatic actuator apart is its integrated spring return mechanism, which ensures fail-safe operation. In the event of air supply failure, the actuator automatically returns the valve to its default position, thereby enhancing safety and operational reliability.

► Compliant with industry standards – Designed to meet ISO5211 standards, our single acting scotch yoke pneumatic actuator is a reliable and efficient choice for your valve system.

► High torque output – Capable of up to 250,000Nm (184,000 foot-pounds) of torque, our actuator can handle even the most demanding applications with ease.
► Enhanced performance – Our shift fork design reduces lateral loads for smoother operation and improved performance. Plus, its modular structure allows for easier maintenance and part interchangeability.
► Built to last – With a cylinder module featuring a built-in guide rod, our actuator prevents wear on piston seals and ensures long-lasting and stable output. Oil-free lubricated bearings also provide durable and consistent performance.
► Versatile options – Choose from manual operating mechanisms such as handwheels, gear transmission, or hydraulics. We offer symmetrical or tilted shift forks for customization to fit your needs.
► Fail-safe operation – Easily switch between single-action fail-open or fail-close modes by changing the direction of the cylinder and spring module. Efficient and convenient for regulating applications.

Design Parameters

Torque range：
– Double-action: 250,00ONm (184 000 ft lbs)
– Single-action: pneumatic 250,000Nm (184 000 ft lbs)
Spring 110,000Nm (81000 ft lbs)

Air supply pressure
3.5~7BAR (51~101psi)
Air, nitrogen or other pure gases

Temperature range
Normal temperature: -29°C~80C ( -20°F~176°F)
Low temperature: -40°C~80°C ( -40°F~176°F)
Ultra low temperature:-60°℃-80°C (-76°F~176°F)
High temperature: -29°C-160°C ( -20°F~320°F)

Adjustable stroke (0-90°)±6° , total stroke range:80~100°

A Scotch Yoke Pneumatic Actuator is specifically designed to operate quarter-turn (90° rotation) valves, making it an essential choice for industries requiring efficient and powerful torque delivery. These actuators are particularly well-suited for butterfly valves, ball valves, and plug valves, as well as dampers and other rotary motion applications.

Butterfly Valves – Common in pipelines, water treatment, and chemical processing due to their lightweight and compact design.
Ball Valves – Used in oil and gas, petrochemical, and power plants due to their superior sealing capabilities.
Plug Valves – Common in applications involving viscous fluids, slurries, and abrasive media.

Applications for a Scotch Yoke Pneumatic Actuator in the industry
Oil & Gas: actuate valves for isolating flow in pipes
Mining: actuate valves for isolating nozzles in rocks washing lines
Water and wastewater: actuate valves for isolating feed lines, filters and tanks
 

Scotch Yoke Pneumatic Actuator Explained

The Scotch Yoke Pneumatic Actuator is a mechanical system that converts rotational motion into linear motion or vice versa. It consists of a sliding yoke with a slot, a crank or pin, a piston rod, and a fixed link. As the crank rotates, the attached pin moves within the slot of the yoke, forcing the yoke to move linearly. This design provides a smooth sinusoidal motion with high torque output at specific points in the cycle.

Key Components:

► Crank (or Pin): Rotates to drive the mechanism.
► Yoke (Sliding Block): Contains a slot that guides the pin's movement, resulting in linear displacement.
► Piston Rod: Connects the yoke to the piston, transferring linear motion for applications such as engine pistons, actuators, or compressors.
► Fixed Link: Serves as the pivot point for the crank's rotation.
 

Hot Tags: scotch yoke pneumatic actuator, China scotch yoke pneumatic actuator manufacturers, suppliers, factory