Patent ID: 7875169

Claim:
A leakage indicator for a filter element of a filter press, the filter element having at least one membrane to be impinged by a pressure medium, the leakage indicator comprising: a flow chamber having an arcuate shape, said flow chamber being defined by a separating element and a circular surface opposite said separating element and also by two opposed substantially planar surfaces, said flow chamber having a central part with a cross section, and said flow chamber having end portions interconnected by said central part, said end portions having cross sections greater than said cross section of said central part and said end portions being connected to the filter element to permit the pressure medium to flow between the filter element and said end portions, said flow chamber having ends and an inlet opening and outlet opening respectively disposed at said ends; an indicator body freely movable in said flow chamber permitting a change in position of said indicator body caused by inflowing or outflowing pressure medium from or to the filter element, said change in position to be monitored visually or by sensors, said indicator body being dimensioned for maintaining an adequately large open cross section for unhindered filling and emptying of the filter element, when said indicator body is positioned in one of said end portions; and shut-off elements disposed at said ends of said flow chamber and preventing blocking of said inlet and outlet openings by said indicator body.