Filters that provide a bypass for the flow rate around the filter, if the has reached a defined value. The filter function is then disabled, such that its effectiveness is reduced (Figure F 11).
The bypass valve is intended to protect the filter element against destruction before its strength limit is reached, as otherwise the contamination collected will be returned to the circuit.
A filter with bypass should never be used without an effective visual clogging display.
Figure F 11: Filter with bypass valve