LHS Hydraulic Scotch Yoke Heavy-Duty Actuator
The Limitorque Hydraulic Scotch Yoke (LHS) heavy-duty is a piston-type, scotch yoke actuator designed to meet or exceed the most current and stringent safety and reliability standards for application in the oil and gas industry. It is ideal where hydraulic motive power is preferred and for services requiring a robust design, long service life, high-torque and high-speed operation. The powerful LHS Hydraulic Scotch Yoke Actuator delivers torque ranges up to 250 kNm (184 000 ft-lb); for larger output torques contact Flowserve.
Crude Oil Transfer, Water Supply and Distribution (water), Desalination, LNG, FPSO, Filtration, Power Generation, Gas Production, Gas to Liquids, Heavy Oil, Oil Sands and Shale, Hydrocarbon Processing, Chemical Processing, Marine, Offshore, Nuclear Service, Oil Production, Petrochemical Processing, Petroleum Production and Refining, Pharmaceuticals, Drilling and Production
Nuclear Power, Chemical Processing, Water Handling and Treatment, Power Generation, Oil and Gas
ISO 9001, EN 15714
The Limitorque Hydraulic Scotch Yoke (LHS) Actuator is suitable for use in on/off, modulating and control applications of quarter-turn valves in general service and protective services. It can also be used in safety services such as emergency shutdown (ESD) or high-integrity pressure protection systems (HIPPS), up to and including SIL 3 Level in accordance with IEC 61508. Among the most important benefits of this product:
- Industry-leading, 25-year design life, depending on service conditions, proper installation,, operation and maintenance
- Maintenance intervals up to six years or as prescribed in EN 15714 for high-cycle applications
- Warranty terms exceeding typical industry norms
- Modular construction to reduce initial cost, minimize repair cost and maximize process availability
- 207 barg (3000 psig) maximum allowable working pressure (MAWP); a 345 barg (5000 psig) version is available upon request
- Easy on-site maintenance without special tools and without removal from the valves for standard maintenance activities
- Up to 250 kNm (184 000 ft-lb) of torque; consult factory for larger sizes and higher torques
- Quick stroking times — less than 0.5 seconds, subject to technical evaluation
- Operating temperature range from -29°C (-20°F) for spring-return units and -60°C (-76°F) for double-acting units up to 160°C (320°F); polar, cold, arid and tropical temperature requirements in accordance with IEC 60721
Custom controls packages upon request for most applications, including hydraulic control panels, hydraulic power units, hydraulic accumulator racks and self-contained units. Electro-hydraulic integrated solutions can be further designed and developed for special applications upon request.
Heavy-duty design features a robust construction with high-strength materials that deliver maximum force while minimizing localized stresses, providing the most rugged actuator available. Fabricated carbon steel scotch yoke housing and spring cans, Electroless Nickel plated hydraulic cylinders and Chrome plated piston rods; different materials of construction for polar or offshore applications upon request. The LHS is designed for a maximum allowable working pressure of 207 barg (3000 psig) with a 345 barg (5000 psig) optional version. Its low displacement design reduces operation and controls package costs. The actuator is available in single-acting spring return (Fail Close CW and Fail Open CCW) and double-acting (Fail Last / Fail as Is) configurations.
Reliable, compact, high-cycle yoke design minimizes transverse loads. A symmetrical yoke is standard, and a canted yoke is available optionally. The torque module includes numerous heavy-duty features, including:
- Guide block for directional alignment of linear forces, transfer of side loads to the guide bar, and transfer of torque to the yoke
- Slider block with optimized surface areas for long life, minimal wear and increased efficiency
- Easy replacement of Seals and Sliding Blocks, without actuator disassembly from the valve
- High-strength yoke pin for maximum torque transfer while minimizing wear and localized stresses
- Maximized valve bore and a closed-yoke design
- Modular design for flexible and easy field conversion from Fail Close CW to Fail Open CCW configuration or vice versa
- On-site maintenance without need of special tools
Rapid emergency response in less than 0.5 seconds achieved through optimized design. The LHS is designed with emphasis on ever-increasing requirements for high torque and fast response time. The result is the smallest possible displacement volume for given torque outputs, resulting in the fastest possible cylinder exhaust, making it ideal for emergency applications such as EDS and HIPPS.
Standard and Custom Controls
Limitorque offers a selection of standard and custom controls packages for most applications, including:
- Hydraulic control panels
- Hydraulic power units (HPU)
- Hydraulic accumulator racks
- Self-contained units (SCU)
- Electro-hydraulic integrated solutions upon request
Lockout modules, manual overrides, other controls and accessories are available from Acrodyne’s Melbourne warehouse.