We offer an array of manual and motorizable gearboxes (actuators).

The actuators can be ordered with specifications to suit the wide variety of environments and media encountered by our customers. These specifications are continually developed as the needs of the marketplace demand. Currently, there are 33 different designs ranging from low temperature to fire safe to nuclear environment. All of our products can be customized to satisfy mounting patterns and valve stems in an infinite variety for all valves. Contact us for more information and to find the best product for your application and requirements.

MF Series 12 Gearbox M12 Gearbox Bevel Gear Gearbox


Today, nuclear power generation demands more from hydraulic and pneumatic actuators than ever before. Greater pressures. Higher speeds. Closer tolerances. Zero leakage performance. Servo/proportional system response. This is why DG Services has partnered with Hanna Nuclear as an authorized distributor.

Our quarter turn and rising stem nuclear actuators are constructed to withstand severe duty applications. All of our nuclear actuators are manufactured in accordance to the standards of our 10CFR50 appendix B quality assurance program.

Actuators: Quarter-turn and Linear Rising Stem

  • Custom designs available with spring return (fail open/closed) and fitted with a variety of options.
  • Designed to meet the rigorous requirements for the next generation of nuclear power plants (AP1000).
  • Experience with air manifold panels, dump valve assemblies, solenoids, and any other type of pneumatic add-ons for actuators.
  • Nuclear qualified quarter-turn units

Functional Performance Parameters

  • Minimum Output Torque Delivery: 19,000 in-lbf (1,583 ft-lbf)
  • Minimum 90-degree rotation, with slight over-travel to ensure proper valve seating
  • Nominal 80 psig pneumatic inlet operating pressure
  • Qualification Methodology conducted in accordance with IEEE 382-1996, IEEE 344-1987, IEEE 323-1974

Qualified Design-Life Characteristics

  • Thermal Aging: 60+ year environmental operating life
  • Mechanical (Cycle) Aging: 30,000 full-open to full-close operating cycles under load
  • Radiation Exposure: 67 MRad (670 kGy) TID, Gamma (Cobalt-60 Source, Air Equivalent)
  • Combined Normal and Design-Basis Event Exposure
  • Environmental Vibration Exposure: 90 minutes per axis, 0.75g (limited to 0.025” peak-peak amplitude)
  • 2 octaves per minute, sinusoidal sweeps (5-100-5 Hz)
  • Design-Basis Event Seismic Qualification: Required Input Motion (RIM) – 4.4g OBE, 6.6g SSE (ZPA)
  • Random Multi-Frequency (Tri-axial): 11.9g Spectral Acceleration, 2g ZPA
  • Design-Basis Event Loss of Coolant Accident (LOCA) Qualification: Initial ramp rate of 820°F/s for 0.25 seconds and a maximum temperature of 445°F, Chemical Spray – 2700 ppm Boric Acid for first 3 hours, 7.53g/L Trisodium Phosphate Dodecahydrate for 21 hours
  • Functional tests: Completed at 20 second mark and at 860 second mark