This is a versatile filter, which can be directly welded into a reservoir’s suction and return line or conversely installed in pipes with a maximum pressure of 10 kg/cm2 (142 psi). This filter can remove particles as small as 3 u. It consists of an indicating element, which indicates the time when cleaning is required. That is why this filter is referred to as a telltale filter (Figure 7.8).
The operation of a tell-tale filter is dependent on the fluid passing through the porous media, which traps the contaminants. The tell-tale indicator monitors the pressure differential buildup due to dirt, which gives an indication of the condition of the filter element.
Long, long time ago ( in the sixties?), I was working with the Dutch hydraulic company Hydraudyne /Boxtel.
We where representing TellTale filters for quote some years.
I came across the word tell tale in the book Ulysses by James Joyce when he is discribing the eyes of a pretty girl.
And that brought back good memories.
Jan Zwanenberg