Ship sanitary system is also known as domestic sea water system.
The system is mainly used for flushing of toilets. The system consists of a hydrophore tank (pressurised tank) for storage of sea water. The tank is pressurised by compressed air (pressure about 6 bar) for pumping sea water to accommodation spaces. The filling of the tank is by means of a two self-priming centrifugal pump (one working + one standby) which take suction from the sea and discharge to the tank.
Starting and stopping of pumps is automatically controlled by a pressure switch mounted on the tank. In a case of low pressure in the tank (due to consumption of water) the pressure switch activates the starter of the pump to start. In a case of high pressure (when the tank is full) the pump automatically stops (activated by pressure switch).
The piping shall be galvanised steel piping or copper piping. The materials used for the manufacture of pumps shall be sea water resistant. (casing – bronze; impeller – bronze; shaft – stainless steel).