OLGA/OLGAS high pressure actuators

Double-acting and spring return hydraulic quarter-turn actuators for on-off and modulating control of valves in heavy duty service. Models available for output torques to 750,000 Nm.

Features & Benefits

  • Totally enclosed, weatherproof housing in fabricated carbon steel for maximum strength.
  • Guide bar resists transverse loads and supports the piston rod.
  • Hard chromium plated alloy steel material guarantees corrosion protection and minimal friction.
  • PTFE-impregnated bronze or sintered bronze bushings provide minimal friction and extended service life.
  • Scotch yoke design with canted or symmetric torque arm allows close working to distinctive valve torque profiles.
  • External travel stops for precise angular stroke adjustment between 82° and 98°.
  • Electroless nickel plated and polished cylinder provides maximum corrosion resistance and reduces friction.
  • Triple-element piston seals provide low friction, high sensitivity, ensure long life and prevent sticking problems.
  • OLGAS fully encapsulated spring return pack with up to four springs, ensures personnel safety and simplifies assembly.
  • OLGAS modular design enables spring action to be changed in the field easily.
  • OLGAS-QA achieves ‘safe’ position in 0.2 second.


General application 
OLGA and OLGAS series hydraulic actuators are designed for the control of quarter turn ball, butterfly, plug or damper style valves. 

Safety integrity level: 
(IEC 61508-1÷7:2010) – Suitable for use in SIL3 applications 
Area classification: 
(ATEX) - II 2GD 135°C (T4) 
Enclosure standards: 
(IEC 60529) - IP67M 
(ANSI/NEMA 250) - NEMA 4, 4X, 6 
Pressure equipment directive: 
PED 97/23/EC 
Machinery directive: 

Technical data
Design pressure: 
OLGA/OLGAS: 105 bar g maximum  
OLGAS-QA: 30 bar g maximum  
Supply medium: Hydraulic oil 
Special versions for fireresistant fluids 
Output torque
OLGA: Double acting torque up to 750,000 Nm 
OLGAS-QA: Spring starting torque up to 335,000 Nm 
Spring ending torque: 235,000 Nm 
Higher values available with special versions 
Ambient temperature 
Standard range: -20 °C to +100 °C (-20°F to + 210°F) 
Extended range: -60 °C to +100 °C (-70°F to + 210°F) 

Documents & Drawings

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