Troubleshooting Proportional Valve Systems


Public One-Day Workshop

Call (770) 267-3787 to Register!

April 18th, 2017

Atlanta (Monroe), GA

The Workshop

Proportional valves are many times changed without any tests being performed. In addition, the adjustments on the amplifier or in the PLC are often made without consideration given to how the hydraulic system will be affected. This can be expensive, both in parts cost and plant downtime. In many cases, hours are spent just determining if there is an electrical or hydraulic problem.


This workshop is taught by an instructor who has had years of experience teaching and troubleshooting proportional valve systems. Students are actively involved in hands-on exercises on the proportional valve trainer.  Hydraulic animations are used throughout the workshop to demonstrate the operation of both single and two stage valves. After attending this 8-hour course, the maintenance personnel will know:


  • How a four position, direct solenoid operated proportional valve works.
  • The two purposes of a blocking valve in a proportional valve system
  • The setting and troubleshooting of the hydraulic power supply components; the pressure compensating pump, relief valve, accumulator, and automatic dump valve.
  • The function of the three electrical signals fed into a proportional valve amplifier.
  • How the current to the valve coil determines the amount that the valve spool shifts.
  • The purpose of the LVDT (linear variable differential transformer) located on the proportional valve.
  • How to check the LVDT feedback signal
  • How to mechanically and electrically null a direct operated valve.
  • The three factors that determine the speed of a cylinder or motor when controlled by a proportional valve.
  • The function of the hydrostat when used with a proportional valve.
  • The two types of “power off” valve spools and why each is used.
  • The function of the lights and adjustments on the amplifier.
  • How to check the power supply, enable, command and LVDT feedback signals.
  • How to troubleshoot the direct operated proportional valve.
  • How a two stage proportional valve works.
  • The purpose and location of the Allen head plugs in a two-stage valve.
  • How to convert externally piloted and drained valves into internally piloted and drained valves.
  • The composite symbol that is commonly shown on the hydraulic schematic for a two stage proportional valve.
  • How to check the electrical inputs and outputs on a two stage valve amplifier.
  • How to electrically and mechanically null a two-stage valve.
  • How the linear positioner operates.
  • How to drive and troubleshoot a proportional valve with a test box.
  • The proper filtration required for proportional valves.

Troubleshooting Proportional Valves Manual

Our Hands-On Proportional Valve Trainer