Interface Valve Chamber

Sewage flows from the building through normal gravity pipes into the lower section, or wet sump, of the interface valve chamber.

As the level of the effluent within the wet sump rises the pressure inside the sensor pipe increases. This is transferred through the flexible tubing to the top section of the Redivac interface valve, known as the controller.

Once the pressure reaches a preset level a switch within the controller operates allowing vacuum to be transferred to the main body of the valve. This in turn pulls the plunger back and opens the interface valve to the vacuum sewer.

Air at atmospheric pressure acting on the surface of the liquid within the wet sump then forces the sewage into the suction pipe and through the Redivac interface valve into the vacuum sewer.

Once all of the sewage has been removed from the wet sump, the Redivac valve remains open for a short period of time to allow air at atmospheric pressure to enter the sewer pipe network. This air helps break up the effluent and allows it to travel through the vacuum sewer at up to 6 metres per second as a foaming mixture of liquid and air.

Once the wet sump is empty and the pressure within the sensor pipe returns to normal atmospheric pressure, the Redivac valve closes completing the cycle.