Pressure Limitation Valves
Installation, Function, Usage Example
The valve is connected in parallel in the bypass line (between supply pump and fluid outlet).
Physical procedure during pressure control:
With the valve seal, the bypass valve has a pressure-active area AM. Together with the dynamic pressure of the medium pM a medium force FM develops. This force effects an opening of the valve.
FMedium = AMedium · pMedium
This medium force FM acts against a drive force FL. FL is determined by the area of the drive piston AL and the variable pneumatic pressure PL. This drive force effect a closing of the valve.
FAir = AAir · pAir
Equilibrium of forces (pressure balance) is then prevalent if:
FL = FM and therefore pactual = ptarget
If the system pressure is greater, then FM will be greater than FL. The consequence of this is that the valve opens so long until the equilibrium of forces prevails. Surplus medium is conducted away unpressurised after the valve. If the system pressure lessens, then FM will be smaller than FL. The consequence of this is that the valve closes so long until the equilibrium of forces prevails.