• It is important for plumbers to know how the drainage systems work.
• Waste enters the DWV system from the fixture drain and flows into the building's sanitary pipe systems. The DWV system must be installed at a slope toward the point of disposal.
• Some of the major components of a DWV system include the building drain, soil stack, vents, fixture branches, traps, tees.
• Water seal in a trap prevents a trap from malfunctioning, i.e. it prevents the sewer gas from entering into the building.
• A trap can lose its seal in a number of ways which includes siphonage, aspiration, momentum, oscillation, back pressure, evaporation, capillary attraction, and cracks.
• Drainage fittings such as bends, cleanouts, tees, and wyes are used to connect various plumbing pipes. Cast iron and plastic are the most commonly used materials used to make DWV fittings.
• A conventional septic tank is a type of private waste disposal system. It consists of a septic tank, a distribution box, a leach field, and connecting pipes.
• DWV systems must be designed and installed as per the local plumbing codes. These codes protect the safety, health, and welfare of the public.