Water and Drains Glossary Part 2
Storm sewer—A sewer used for conveying rain water, surface water, condensate, cooling water, or similar liquid waste.
Trap—A fitting or device that provides a liquid seal to prevent the emission of sewer gases without materially affecting the flow of sewage or wastewater through it.
Vacuum breaker—A device to prevent backflow (back siphonage) by means of an opening through which air may be drawn to relieve negative pressure (vacuum).
Vapor lock—A bubble of air that restricts the flow of water in a pipe.
Vent stack—The vertical vent pipe installed to provide air circulation to and from the drainage system and that extends through one or more stories.
Water hammer—The loud thump of water in a pipe when a valve or faucet is suddenly closed.
Water service pipe—The pipe from the water main or other sources of potable water supply to the water-distributing system of the building served.
Water supply system—Consists of the water service pipe, the water-distributing pipes, the necessary connecting pipes, fittings, control valves, and all appurtenances in or adjacent to the building or premises.
Wet vent—A vent that receives the discharge of waste other than from water closets.
Yoke vent—A pipe connecting upward from a soil or waste stack to a vent stack to prevent pressure changes in the stacks. Definitions of Terms Related to Home Water Systems