Deadband in hydraulic pressure switch.

Hi Mansilakhani

I think what you mean is "Hysteresis" which is the difference between a rising pressure switch point and a falling one. ANYTHING that contains a spring suffers from this problem.

To answer your question accurately is difficult as all springs have different characteristics. However, an average hydraulic pressure switch may likely have a 0.5 Bar differential. You do tend to pay for accuracy!

Good luck with it!

This is really depending on the type of switch. Since the switch is a valve to be opened or closed, the traveling distance to do this determines the movement band for e.g. a stop switch that is activated with a moving object. here you switch hydraulics. This applied to a pressure switch where also movement is needed, the counter force is mostly applied with a spring (fixed or adjustable) or a pretensioned membrane that activates a tumbling mechanism to switch. You have e.g. a switch for oil pressure in motor blocks, low range 2-4 bar fixed and pressure switches up to 700 bar in hi pressure hydraulic systems. Here you open or close a electrical contact. Your supplier will specify the dead band for a specific application.

The question is not meaningful. No one should care about some average deadband (or hysteresis); instead one should focus on the control requirements of the specific application.

Deadband (Differential, Actuation Value) - The difference between the actuation point and the deactivation point. For instance if a pressure switch reaches its actuation point and closes the snap action switch at 100 psi, it is in an actuated condition. If the pressure then drops and the switch deactivates (returns to its normal condition) at 90 psi, it is said to have a deadband of 10 psi