Ratgeber zur Auswahl von Drossel- oder Stromregelventil

The choice between flow control (throttle) valves and pressure-compensated flow (flow control) valves can have significant consequences.

Therefore we have explained the basic technical details below:

• What is the fundamental difference between throttle valves and flow control (pressure-compensated) valves?

  • The flow through a throttle valve is pressure-dependent, i.e. if the pressure drop across the valve increases, the volumetric flow also increases. This causes, for example, the actuator speed of hydraulic cylinders to be load-dependent.
    A pressure-compensated flow control valve is load-compensated in this respect; regardless of the back pressure, it maintains a constant flow rate.

• Do I need a throttle or flow control valve with an integrated check valve?

  • For flow control (pressure-compensated) valves a check valve is always required if they are to be flowed through in reverse. For throttle valves it depends on the application. It is also sensible to use them when regulating the extension speed of hydraulic cylinders. With two throttle or two flow control valves with check valves, extension and retraction speeds can be adjusted independently.
  • Attention!
    • Without a check valve it is important to install the valve on the piston-rod side, otherwise an excessive pressure build-up can occur.

• What is the difference between 2-way and 3-way flow control valves?

  • 3-way flow control valves direct the excess volumetric flow to an additional port. Depending on the valve, this excess flow can be used for other applications.
  • 2-way flow control valves block the excess volumetric flow.

Good to know!

• In constant-flow systems, if a continuous flow is present, a 3-way flow control valve should be used so that the system does not run constantly against overpressure. The excess volumetric flow can simply be returned to tank.
• In load-sensing or other closed-center systems, 2-way flow control valves should be used for continuous flow so that the pumps can reduce the volumetric flow to the desired value.