After use by the various sanitary appliances and appliances, the water enters the exhaust system through a siphon and, through the pipes, is conveyed into a braga.

The siphon has the main function of avoiding the return of bad smells at home.

The braga is located under the WC and is connected to the upright column.

The riser in turn reaches the collector that collects the drains of all the riser columns and conveys them into the drainage system to which it is connected via a siphon.

The upstream column of the exhausts requires a vent, generally located on the roof of the house. This secondary piping is called "ventilation" and contributes to the elimination of the typical bubbling of the exhaust.

In case there are drainage pipes placed at a lower level than the sewage system (for example the drainage pipes coming from the cellars) they will be conveyed into a septic tank.

When the septic tank is filled, a pump activated by a level float starts, which directs the black water into the external sewer