7FUG 2020: Parker Hannifin Corporation – Combined Cycle Journal

7FUG 2020: Parker Hannifin Corporation

Parker Hannifin's Jet-Pipe Servo Valves


James Hoke - Capital Projects Manager - Power Generation

Jim started his career with Parker Hannifin while studying for his mechanical engineering degree at the University of Cincinnati. Over the course of almost thirty years, Jim has held multiple roles within Parker's manufacturing and sales organizations, culminating in his current role as the capital projects manager on Parker's Energy Team. Jim's main day to day responsibilities revolve around working with engineering companies to ensure that Parker's broad range of products are recognized and specified, and to find the best way to support field construction needs. Jim and his wife Cassie currently reside in Tucson, Arizona.

Presentation Synopsis

Parker's 1996 acquisition of American Brake Shoe (Abex / NWL), as a compliment to it's wide range of Aerospace offerings, brought with it a unique, robust electrohydraulic servo valve. This servo valve is utilized to control the movement of flight control surfaces, converting electrical signals to accurate hydraulic motion. The valves Jet-Pipe (registered trademark) design ensures that flight control surfaces continue to move, even when the hydraulic fluid power system becomes contaminated. These advantages have led to General Electric's approval and use of these valves on their gas and steam turbines, for natural gas and liquid fuel control, steam valve actuators, inlet guide vane, and stop ratio actuator use.

Key Takeaways for Users

  • Robust, "soft fail" electrohydraulic servo valves - If plugged will not cause downstream actuator to fully extend or retract, but remain in place. May also be spring biased in order to control actuator to preferred safe position.
  • Drop in replacements for many currently used servo valves, including hydraulic mounting and electrical connections.
  • Contaminant tolerant - large orifice diameters allow contaminants to pass through instead of obstructing flow.
  • Hydraulic spool designed with a sizeable chip shear force - enabling the valve to continue operating in hydraulic systems experiencing varnish build-up.
  • Extended operating time between preventative maintenance / calibration / clean-check-test due to robust design. This helps to reduce cost of ownership, eliminating control drift or unwanted turbine trips.


James Hoke / jhoke@parker.com / 440-823-3453 (mobile)

About Parker Hannifin Corporation

Parker Hannifin is one of the largest and oldest motion and control manufacturers in the world. Founded in Cleveland Ohio in 1917, Parker was instrumentation (Change this to instrumental) in the development of the aviation industry, leading to it's role in today's commercial / military aircraft, and the use of combustion turbines. Parker's 6 operating groups (Filtration, Instrumentation, Motion Systems (Hydraulics), Aerospace, Fluid Connectors and Engineered Materials (Sealing) all manufacture products used in power generation.

Products and Services

  • Filtration - hydraulic, water, air, fuel oil, specialty gases, etc.
  • Electromechanical control of gas and steam valves, inlet guide vane actuators, stop ratio valves, etc.
  • Fluid connectors - tubing compression fittings and valves, hydraulic and pneumatic fittings, hose, heat tracing, etc.
  • Motion Control - pumps, cylinders, accumulators, control valves, etc.
  • Seals - turbine casing seals, on engine turbine seals, O-rings, etc.
  • Aerospace derived components - fuel nozzles, lube oil scavenge pumps, inlet fogging nozzles, etc.




6035 Parkland Boulevard
Cleveland, Ohio 44124
United States

Scroll to Top