Product Detail

79 Series

Quick Overview


Mounting Surface: Moog Standard

Max Pressure: 3000 to 5000 PSI (210 to 345 bar)
Rated Flow Rate: 30 to 260 gpm (114 to 984 l/min)

The 79 Series flow control servo valves are throttle valves for 3 and preferably 4-way applications. These three stage servo valves were developed for applications that require high flow rates and high performance. The 79 series covers the range of rated flow from 30 to 200 gpm at 1,000 psi valve drop. These valves are offered with 76X Series pilot valves, in either Standard, High, or Very High performance configurations.

These valves are suitable for electrohydraulic position, speed, pressure, or force control systems with high dynamic response requirements.

An electrical command signal (set point, input signal) is applied to the external control amplifier which drives a current through the pilot valve coils. The pilot valve produces differential pressure in its control ports. This pressure difference results in a pilot flow which causes main spool displacement.

The position transducer, which is excited via an oscillator, measures the position of the main spool (actual value, position voltage). The signal then is demodulated and fed back to the control amplifier where it is compared with the command signal. The control amplifier drives the pilot valve until the error between command signal and feedback signal is zero. Thus, the position of the main spool is proportional to the electrical command signal.

  • Electrical feedback on the main spool for low hysteresis and excellent linearity
  • Optional external pilot supply and return connections
  • High spool control forces
  • High dynamics
  • Rugged, long-life design
  • High resolution, low hysteresis
  • Completely set-up at the factory
  • Excellent null stability
100 200
Rated Flow Per Spool Land (Δ 1000 psi/70 bar) 30 gpm 114 l/min 100 gpm 379 l/min
60 gpm 227 l/min 200 gpm 757 l/min
- - 260 gpm 984 l/min
Max Operating Pressure F 3000 psi 210 bar
J 4500 psi 310 bar
K 5000 psi 345 bar
Viscosity Range 42 to 5787 SSU at 100 °F 5  to 1250 cSt
Temperature Range -40 to +140 °F -40 to +60 °C

Product Specifications