| Drain-waste-vent, or DWV, is a type of plumbing | | | | fixtures directly to the outdoors, often through the |
| systems in which sewage is taken from a building and | | | | roof. Vents serve several purposes; they allow an |
| noxious gases are vented. Waste enters the DWV | | | | outlet for sewer gases, they encourage oxygen |
| from plumbing fixtures such as toilets, sinks, bathtubs | | | | circulation which allows sewage to begin to |
| and showers. The waste exits the fixtures through a | | | | decompose, and they prevent sewer gases from |
| dipped section of pipe called a trap, which maintains a | | | | entering the building. With few exceptions, every |
| constant supply of water. All plumbing fixtures must | | | | plumbing fixture is required by building codes to have |
| have traps to prevent gases backing up into the | | | | an attached vent. These vents are sometimes |
| home or building, with rather unattractive and | | | | descriptively called stink pipes. |
| unhealthy results. | | | | Because gravity is the force powering these plumbing |
| Traps connect plumbing fixtures to a common waste | | | | systems, it is critical that all pipes have a downward |
| line, which channels waste to what is euphemistically | | | | slope throughout the system. In instances where a |
| called a soil stack. The waste is then removed from | | | | downward slope out of a building and into the sewer |
| the building through a main drain and taken to a | | | | cannot be created, a collection pit and grinding lift |
| sewage line. | | | | 'sewage ejector' pump are used to deliver waste to |
| The venting system pipes are an important part of | | | | the sewage system. |
| any plumbing system. It is their job to connect | | | | |