The waste outlet of the bathtub is connected to the sullage pipe through _________,

Trap:

• A trap is a depressed or bent sanitary fitting that always remains full of water and connects the sullage pipe
• They prevent the entry of foul air, insects, and parasites from the sewers into the building and resist the spread of diseases. Traps are constructed so that they retain a body of water that acts as a water seal.
• Traps should be of the self-cleaning type. They should generate enough speed from the available flow to create a self-cleaning effect, i.e. a smooth finish and a full identical opening.

Type of traps:

Intercepting trap: It has a water seal of about 100 mm, and it is provided in the last manhole of the house drainage system. It thus conveys sewage from house to the public sewer. The main idea of providing the intercepting trap sewer trap is to prevent the entry of sewer gases from public sewer line into the house drains.

P - trap: This trap has the shape of letter P and has a depth of water seal varying about 25 mm to 75 mm.

Floor trap: A floor trap is made of cast iron or P.V.C and it is provided at the point of entry of wastewater in the house. This trap is also referred to as the nahani trap and is generally placed in bathrooms, kitchens, sinks, etc. The minimum depth of water seal is 50 mm.

Gully trap: It is usually made of stoneware and a cast iron grating is provided at its top. It is fitted inside a masonry chamber and depth of water seal is about 60 mm to 70 mm. The gully trap forms the starting point of the horizontal flow of sewage and is situated near the external face of the wall.