Proportional or switching valve - which should you choose?
Proportional valves regulate pressure and flow steplessly instead of just opening and closing. This guide shows when the move from a switching valve pays off and how to select the flow curve, hysteresis and the 0-10 V or 4-20 mA control signal for your task.
View proportional valvesWhen does a proportional valve make sense?
A switching valve has only two states: open or closed. A proportional valve sets pressure or flow steplessly in relation to an electrical setpoint. As soon as a task needs a regulated variable - constant clamping pressure, a soft start or a variable speed - the proportional valve is the right choice.
For pure on-off duty, end positions or simple clamping, a switching valve stays cheaper and more rugged. The extra cost of a proportional valve only pays off when the application genuinely calls for stepless control or ramps.
- Constant clamping or holding pressure regardless of consumption and temperature.
- Soft start and stop via pressure or flow ramps.
- Variable cylinder speed without mechanical flow restrictors.
- Force control in joining, testing or dosing tasks.
Flow curve and hysteresis - what matters?
The characteristic curve describes the relation between setpoint and output. What counts is a curve as linear as possible, low hysteresis and a small deadband near zero. These figures decide control quality far more than the nominal flow rating alone.
Hysteresis is the difference between rising and falling setpoint at the same output. Good proportional valves stay below 1 %, simple designs sit at 3 to 5 %. Low-friction spools and an internal position loop cut hysteresis significantly.
0-10 V or 4-20 mA - which control signal?
The setpoint usually arrives as an analogue signal from the controller. 0‑10 V is easy to generate and ideal for short runs inside the cabinet. 4‑20 mA is more immune to interference over long cables and allows wire-break detection, because 0 mA is read as a fault.
- 0‑10 V: low cost, short distances, more sensitive to voltage drop and pickup.
- 4‑20 mA: robust over long cables, wire break detectable (signal never 0), industry standard.
- Use a common ground and shielded cables to avoid ground loops and hum.
- Digital fieldbuses (IO-Link, CANopen) increasingly replace the pure analogue signal.
Frequently asked questions
When is a proportional valve worth it over a switching valve?
As soon as pressure, force or speed has to be set steplessly as a controlled variable. For pure on-off duty a switching valve stays cheaper and more rugged.
What does hysteresis mean on a proportional valve?
It is the difference in output between a rising and a falling setpoint. Good valves stay below 1 percent, simple ones sit at 3 to 5 percent.
0-10 V or 4-20 mA - which is better?
4‑20 mA is more immune to interference over long cables and detects wire breaks. 0‑10 V is cheaper and fully sufficient for short runs inside the cabinet.
Do I need an external amplifier card?
Only if the valve has no integrated electronics. Valves with onboard electronics are factory-matched and save wiring effort.
Looking for the right proportional valve?
We supply pressure and flow regulators with 0-10 V or 4-20 mA, integrated electronics and a tested characteristic curve - including sizing advice.
Regulated not switched
Stepless pressure and flow control.
Tested curve
Linearity and hysteresis documented.
Standard signals
0-10 V and 4-20 mA from stock.
Expert advice
Support with sizing and control.