Siemens SINAMICS S120 System Manual page 240

Appendix
A.3 Hydraulic
Flow rate characteristic, linear
The stepless spool movement, and thus the change in throttle cross-section at the control
edges, results in a corresponding flow rate, which is represented as a function of the spool
travel s or of the electrical input signal U (manipulated variable). In addition to the opening
cross-section, the flow rate is also dependent on the pressure drop corresponding to the
fluid-flow law:
Q ∼√ Δp
Figure A-6
Figure A-7
240
Linear flow rate characteristic
Control window in the spool sleeve
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Hydraulic Drive