DWV  is actually a jargon of the plumbing field and is a short of Drain, Waste, and Vent. It is a part of a plumbing system that is very functional: it removes the waste from the roof,  from the home and vents,  it keeps away the odors and dangerous biological gases created by the waste. This venting type maintains an equalization of air and/or water pressure throughout the DWV system and this way the toilets won’t have water pulled out of them. This siphoning action leaves the house exposed to sewage gases.
DWV pipes and fittings are usually made of metal such as cast iron, copper, and lead. But, today, the plastic pipes and fittings are majority used for DWV systems. They cost little and are quick for assembly, many people try to arrange them as a DIY project for their homes.

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