During the initial commissioning or repeat commissioning, every hydraulic System must be flushed to remove residual foreign particles (shavings, scale or other contamination) from the system.
The flushing takes place at a low pressure. Here the filters are to be carefully monitored, as they can become blocked quickly under certain circumstances. Sensitive devices, such as servo valves should not yet be installed.
The flushing is to continue until the desired degree of purity has been achieved (Figure S 77).
As with this process, the system pump is completely exposed to contamination, it is recommended to use a flushing power pack with its own pump (normally a gear pump) for the flushing. In addition, separate flushing liquid may be used.
Figure S 77: Change of the residual contamination over time during flushing