GP (pneumatic) and GH (hydraulic) range scotch yoke actuators are designed to provide a rotary, quarter-turn movement for either on/off or modulating duty. The rugged yet compact design is available with two different yoke designs. The classic symmetric yoke delivers peak torque at both ends of stroke. Alternatively, they can be supplied with canted torque arms designed to deliver peak torque at only one end of stroke. Use of canted arms can often reduce actuator size, weight and cost for valves with appropriate torque demand characteristics.
Proven, Dependable Design
GP and GH range scotch yoke actuators are designed to operate ball, butterfly and plug valves requiring a rotary, quarter-turn movement for either on/off or modulating duty. The robust design has been proven in thousands of diverse applications the world over.
Safety by Design
Spring-return units can be assembled to provide failsafe operation in either direction. The spring-return module is inherently safe since it can only be removed from the centrebody after all spring forces have been released. Centrebodies incorporate a pressure relief valve.
TWo Torque Output Profiles
GP and GH range actuators can be supplied with either symmetrical or canted torque arms. The classic symmetric yoke delivers peak torque at both ends of stroke. The canted yoke is a Rotork design innovation that delivers peak torque at only one end of stroke. Use of canted arms can often reduce actuator size, weight and cost for valves with appropriate torque demand characteristics.
Rotork GP and GH range actuators share a modular construction design. The centre body is available in nine sizes. A pneumatic or hydraulic cylinder can be attached to either or both sides. A spring cartridge can also be fitted to either side for Emergency Shut Down (ESD) applications. Modular construction and stocking of components by Rotork Fluid Systems' Centres of Excellence and a worldwide network of distributors facilitates quick delivery times.
Every Rotork Fluid Systems actuator is built to provide long and efficient service with minimum maintenance. The design, engineering and materials used in their construction ensure optimum performance even in the harshest of environments.
Operating Pressure: Pneumatic up to 12 bar (175 psi), Hydraulic up to 210 bar (3,000 psi)
Torque Output: Up to 600,000 Nm (5.3 million Ibf-in)
Standard: -30 to 100 °C/(-22 to 212 °F)
High: -20 to 160 °C/(-4 to 320 °F)
Low: -40 to 160 °C/(-40 to 320 °F)
Extreme Low: -60 to 160 °C/(-76 to 320 °F)
Efficiency and Long Life
Minimum friction is ensured by electroless nickel-platedcylinders and bronze sliding blocks on the torque arm.A dynamic floating piston seal further reduces friction andavoids stick-slip effect, even after prolonged periods withoutoperation.
O-ring sealing provides protection certified to IEC IP66M, IP67M.
Extended service life provided by carbon steel, electroless nickel-plated cylinders and chromium plated piston rod.
Robust Yet Lightweight Design
Totally enclosed weatherproof centrebody fabricated incarbon steel or ductile iron (depending upon size) providean excellent strength to weight ratio. The scotch yokemechanism is available in either symmetric or canted design tomeet application specific valve torque demand requirementswith minimum cost and weight. The design incorporatesa chromium plated alloy steel thrust bar to support thetransverse loads of the scotch yoke.
Manual override solutions. Stainless steel cylinders and tierods. Custom paint specifications. Fibreglide® yoke bushingfor modulating duty applications.
A dependable manual override facility is an important part many valve/actuator applications. Rotork has a variety of override options available to meet virtually any requirement. Available options include open or enclosed jackscrews in both gear reducer and declutchable versions, as well as a number of hydraulic override solutions.
Complete Control Systems
Control component packages are a part of any actuator/valve installation. Rotork has extensive experience in the design and assembly of all types of fluid power control systems to satisfy any customer requirement for on/off, modulating or ESD (emergency shut down) service. Packages can be mounted on a panel or in a cabinet and mounted either on the actuator or at a remote location. Rotork offers components from all leading industry suppliers as well as those of our own design including limit switch housings, quick exhaust valves, pneumatic and hydraulic manifolds, shuttle valves, linebreak safety systems and a torque limiting device.
Fire Protection Systems
Rotork Fluid Systems actuators and control systems can be customized to withstand exposure both to fire and very high environmental temperatures. A range of fire-proof systems is available that include flexible protective jackets, intumescent coatings and rigid enclosure systems. For further information on Rotork's fire protection solutions, consult publication PUB0O0-004.
Extensive Product Range
Rotork Fluid Systems offers the world's most extensive line of fluid power valve actuators. Products include low- and high- pressure pneumatic, hydraulic and electro-hydraulic actuators. Scotch yoke, linear and rack and pinion designs are available in both double-acting and spring-return configurations. We also manufacture special build actuators for subsea and nuclear power applications and specialty products including a hydraulic damper for swing check valves and a manual/ hydraulic power handwheel. Through other divisions, Rotork also offers complete lines of electric actuators and gearboxes.