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