Fluid system for e.g. paper or paperboard machine for producing fibrous material web, has calculation device computing calibration value of valves, on basis of detected piston travel or path between acquisition locations and travel time

摘要

The system has fluid cylinders e.g. double acting cylinders (3), with pressure chambers separated by a piston, and digitally controlled shutoff valves (4) associated to one of the chambers. A position determination device e.g. path sensor, detects a plunger lift or a position detection device e.g. position switch or proximity sensor, detects a piston position at detection locations. A calculation device computes a calibration value e.g. discharge coefficient, of the valves on the basis of detected piston travel or a path between the acquisition locations and travel time. An independent claim is also included for a method for determining a calibration value of a fluid system.