Many hydraulically driven processes require a constant pressure that is independant of flow rate in order to have ideal control. If any of the valves are closed at the inlet to the process the flow rate has to decrease in order for the pressure to remain constant. The controller senses the pressure as feedback and adjusts the pump motor speed accordingly. Designs that rely on a pressure relief valve for excess bypass tend to heat the oil unnecessarily. The pressure relief valve should always be left in place to provide a backup safety system.


  • Accurate pressure
  • Wide range of flow rates
  • Minimized fluid heating
  • Setpoint is pressure