INNOVATIVE AND SAFE DESIGN
AIR BY PASS SAFETY VALVE

When black water tanks are filled they should be pumped out in marina service points or by waste collecting boats. During pumping out, the air flow of the pump is much higher compared to the air flow that should be swallowed through the vent and filter line. This big difference on the flow may damage your tank (collapse, tear weldings, tank sides). To avoid that risk PRO FIL 65 SCC and PRO FIL 80 SCC filters are equipped with an air by pass safety valve. Before pumping out the tank open the air entry nut  with the special tool provided with the filter so that your tank will get enough air flow before vent/filter. Then close it after the operation. So simple!