Pilot Valves

Pilot Valves

The pilot valves main function is to operate larger valves from a remote location requiring less force.

Design

Pilot valves control a reduced flow feed while sending it to another valve, that typically controls a high pressure/high flow feed. Furthermore pilot valves are useful because they allow a small and easily operated feed to control a much higher pressure/higher flow feed. Consequently enabling ease of use that would otherwise require a much larger force to operate. This is also useful when a solenoid is used to operate the high pressure/high flow valve. Finally the valve is made up of sections, each of which contains two 3-way pressure reducing signal ports. In addition up to 6 sections can be stacked into the same valve to give a total of 12 signal ports. The cast-iron valve housing and a hardened, precision-ground steel reducer-valve spool ensures a long service life with minimal internal leaks. Finally special low-friction seals give effective protection against external leakage as well.

[su_table]

Pilot Valves Essential Characteristics

  • Small dimensions enable simple, compact installation.
  • Robust, simple design gives great reliability and easy servicing.
  • Low, well-adapted lever forces and short lever strokes give good operating comfort.
  • Lever forces can be specified per control-pressure port to give function specific actuation resistance.
  • Low hysteresis gives consistent machine-function response to valve actuation.
  • Good metering properties enable gentle, proportional control.
  • Very wide range of control-pressure characteristics enables control of machine functions to be application-optimized.
  • Wide range of control devices and accessories gives great flexibility in system design.
  • Valve can be installed in arm rests of operator’s seat and fitted with site-suited lever to give very ergonomic control station.
  • Quality materials and great precision in manufacturing, assembly and testing assure a quality product with low internal leakage and long service life.
  • Total compatibility with Parker directional valves gives predictable and harmonious system characteristics.

General

  • The data given is applicable at an oil temperature of 50 ºC (122 °F) and viscosity of 30 mm2/s (cSt) using mineral base oil according to DIN 51524.

Pressures

  • Supply pressure (pump pressure)……….max. 100 bar (1450 psi)
  • Recommended supply pressure……….15 bar (218 psi) higher than max. control pressure
  • Control pressure………max. 75 bar (1090 psi).
  • Breakaway pressure……….min. 1 bar (14.5 psi), max. 16 bar (232 psi)
  • Return-line pressure……….max. 3 bar (44 psi)

Flow rate

  • Control flow……….max. 15 LPM (4 US GPM)

Hysteresis

  • Hysteresis……….max. 0.5 bar (7.3 PSI)

Hydraulic Fluids

    • Best performance is obtained using mineral-base oil of high quality and cleanness in the hydraulic system.
      HLP hydraulic fluids (DIN 51524), automatic-gearbox oil type A and API CD engine oils can be used. Synthetic, fire resistant and environmentally friendly fluids can also be used. Please contact Ryan Hydraulic Service for further information about hydraulic fluids.

Viscosity

    • Viscosity, function range……….10-5000 mm2/s (cSt)
      • Viscosity, working range……….10-380 mm2/s (cSt)

    Filtration

    • Filtration should be arranged so that the Target Contamination Class 16/13 according to ISO 4406 is not exceeded.

    Temperature

    • Min. ambient temperature……….–40ºC (-40°F)
    • Max. ambient temperature……….+60ºC (140°F)
    • Min. oil temperature……….–20ºC (-4°F)
    • Max. oil temperature……….+70ºC (166 °F)
    • Temperature change……….max. 100°C/s., max. 212°F/s

    leakage

    • From pump connection to tank connection with the spool in neutral position and a supply pressure of 40 bar (580 psi) max. cm3/min……….(1.22 in3)per control-pressure port

[/su_table]