<P> In modern plumbing , a drain - waste - vent ( or DWV ) is part of a system that removes sewage and greywater from a building , and regulates air pressure in the waste - system pipes to aid free flow . Waste is produced at fixtures such as toilets , sinks , and showers , and exits the fixtures through a trap , a dipped section of pipe that always contains water . </P>
<P> In modern plumbing , a drain - waste - vent ( or DWV ) is part of a system that removes sewage and greywater from a building , and regulates air pressure in the waste - system pipes to aid free flow . Waste is produced at fixtures such as toilets , sinks , and showers , and exits the fixtures through a trap , a dipped section of pipe that always contains water . </P>
what is the purpose of a vent in a plumbing system
what is the purpose of a vent in a plumbing system
regulates air pressure in the waste - system pipes to aid free flow
regulates air pressure in the waste - system pipes to aid free flow