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Damcos™ KF/KFR Linear Single-acting Spring-closing Actuators
Get the fail close performance you demand in a versatile and highly reliable actuator with the Damcos KF/KFR linear single-acting spring-closing actuator.
Operated by hydraulic pressure, the output spindle is lifted (and the valve is opened) and the spring package is compressed. When released the spindle closes on the valve with end closing thrust (spring) of 1500 - 16500 Nm. In an emergency when the hydraulic pressure is not available, a built-in manual hand pump can operate the KFR actuator.
Damcos™ KF/KFR Linear Single-acting Spring-closing Actuators


Burst Pressure
Ambient Temperature
-20 to +80 deg. C
6 to 52 kg depending on type
Oil Displacement
0.021 to 0.428 L
Stroke Height
16.25 to 62.5mm
Hydraulic Media and Viscosities
Acid-free hydraulic oil 15 to 200 cSt (see recommended oil list)
Materials of Construction
Housing in GGG40 – for more detail see Product Data Sheet


  • Unique and simple design with built-in crossover valve
  • No external moving parts during operation
  • Built-in hydraulic emergency operation for KFR
  • Same unit for several valve sizes
  • Easily adapted to all well-known globe valves
  • Prepared for direct built-on modular block functions or LPU
  • Direct visual position indication
  • Electrical on/off or continuous position/indication
  • Roust design operates in any kind of marine environment
  • Advance your system to gain added functionality such as...
  • Flushing valve built into the connection block makes it possible to flush the system without disconnecting pipes, Fail open actuator (KF only)