| Most people think that the plumbing | | | | fresh air prevents suction that would |
| system in a home is more complicated | | | | stop the free flow of drain water. |
| than it really is because of it's | | | | All sewage will eventually reach the |
| network of pipes and valves. Once you | | | | waste and vent stack. The waste water |
| recognize the major components and the | | | | flows in the sewer line and exits the |
| roles they play, home repairs are | | | | house via a municipal sewage system or a |
| relatively easy to do. | | | | private septic tank. In the meantime, |
| Most home plumbing systems are composed | | | | sewer gas rises through the vent and |
| of three things: the water supply | | | | escapes through the roof vent, thus |
| system, the fixtures and appliances, and | | | | rendering it harmless. |
| the drainage system. Water enter a home | | | | Most of the pipes in modern homes are |
| through a main supply line, either a | | | | made of copper but plastic is becoming |
| municipal water company or a private | | | | more popular. Homes build before the |
| well. If it comes from a municipal | | | | 1950's usually had pipes that were made |
| source, it must first pass through a | | | | of galvanized iron. Iron pipes can lead |
| meter which measures the amount of water | | | | to water that looks rusty when it first |
| used. | | | | comes through the fixtures. |
| Once the water from the main supply | | | | Most pipes in the drainage waste system |
| enters the house, the branch line splits | | | | is made of plastic or cast iron. They |
| off and joins the water heater. From | | | | can be one and a quarter inches to four |
| there, the hot and cold water lines run | | | | inches in diameter to allow easy passage |
| parallel to each other to all the | | | | of waste water through the pipes. Lead |
| fixtures and appliances in the house. | | | | pipes are no longer used in home |
| Once the water becomes waste, it runs | | | | plumbing, though for the waste drainage |
| into a trap and then into the drain | | | | system they do not pose a health hazard. |
| system which works totally by gravity. | | | | Slope is an important factor in the |
| Waste water flows downhill through a | | | | waste drainage system, and each section |
| series of large diameter drain pipes, | | | | must have the proper degree of slope to |
| which are attached to a system of vent | | | | allow the system to function as |
| pipes. Vent pipes permit air to enter | | | | intended, working with gravity to remove |
| the system through a roof vent. This | | | | the wastes. |