Ads
related to: air admittance vent for toilet bowl drain
Search results
Results From The WOW.Com Content Network
Air admittance valves (AAVs, or commonly referred to in the UK as Durgo valves and in the US as Studor vents and Sure-Vent®) are negative-pressure-activated, one-way mechanical valves, used in a plumbing or drainage venting system to eliminate the need for conventional pipe venting and roof penetrations.
In the United States, plumbing codes usually provide strict limitations on how far a trap may be located from the nearest vent stack. When a vent cannot be provided, an air admittance valve may be used instead. These devices avoid negative pressure in the drain pipe by venting room air into the drain pipe (behind the trap).
The visible water surface in a toilet is the top of the trap's water seal. Each fixture drain, with exceptions, must be vented so that negative air pressure in the drain cannot siphon the trap dry, to prevent positive air pressure in the sewer from forcing gases past the water seal, and to prevent explosive sewer gas buildup.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Air_admittance_valve&oldid=309883018"
This "air gap" is visible above the sink as a small cylindrical fixture mounted near the faucet. In the base cabinet under the sink, the drain hose from the dishwasher feeds the "top" of the air gap, and the "bottom" of the air gap is plumbed into the sink drain below the basket, or into a garbage disposal unit. When installed and maintained ...
Plastic pipe is in wide use for domestic water supply and drain-waste-vent (DWV) pipe. Principal types include: Polyvinyl chloride (PVC) was produced experimentally in the 19th century but did not become practical to manufacture until 1926, when Waldo Semon of BF Goodrich Co. developed a method to plasticize PVC, making it easier to process.