FS Series Stainless Steel Valve Actuators

FS Series Stainless Steel Valve Actuators

Built to Last 

Due to our belief that actuators should not fail - all QTRCO actuators
feature robust designs and premium materials

FS Series - Materials of Construction

 Mechanism  CF8 Stainless Steel
 Housing  CF8 Stainless Steel
 Cylinders  304 Stainless Steel
 Optional: Amalga Composite or Aluminum
 Pistons  CF8 Stainless Steel
 Springs  Powder Coated Chrome-Silicon Steel
 Optional: Stainless Steel
 Seals   BUNA
 Optional: Viton, Silicon













Patented Flat Yoke® Actuator Mechanism With Quad Body Slots

A unique slotted body concept absorbs 100% of the yoke mechanism's side loading forces leaving the piston rod completely free of bending stresses while allowing termination of the rod at the yoke, and the addition of a weight and force balancing second force module diagonally offset from the first. The balanced weight makes lifting and handling of the actuators safer and easier, while reducing valve neck stress caused by unbalanced scotch yoke actuators. Internally, the balanced forces assure less friction loss and less wear as there is no net force applied to the shaft bushings. Scotch yoke actuators offer a very wide range of torques and can operate on devices that require a quarter turn movement for on/off or various throttling services.

F Series spring return actuator

Higher Torques

By incorporating the patented Flat Yoke® actuator mechanism, higher torque outputs are offered in a weight and force balanced design.

Inherently Canted Yoke

The longer yoke arms of the Flat Yoke® actuator design allow the advantageous canted yoke torque curve simply by choosing a different travel stop setting. This provides substantially more spring end torque without having to purchase a special actuator. As standard, Flat Yoke® actuator travel stops are set to provide a 5 degree canted effect.

Bi-Directional Travel Stops

F actuators feature bi-directional travel stops which allow a minimum of 5 degrees of over travel in each direction. The stops act on the piston motion and impart no side loading on the shaft as occurs with rack & pinion and scotch yoke designs.


The balanced force, close tolerance, and low friction of the Flat Yoke® actuator impart excellent throttling capability.

Torques to 500,000 in-lb
Pressure to 150 psig
Temperatures from -76°F to +450°F | 90° Rotation (±5° at each end of travel)

F series Torque Chart

A proven upgrade to your ordinary scotch yoke actuator

Captured Springs

  • Balanced Weight & Force Distribution
  • Captured Springs
  • Convenient Action Reversal
  • Stainless Steel Construction
  • Spring Return Models Have No Rod Seals



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