Drain, Waste, and Plumbing Vent Systems Explained

Drain waste and vent piping are the two mostHouse Trap and Lateral Line
important components in plumbing. These are theWhen the plumber ties the waste water pipes into the
systems that take water away from your home. Letsewer line, he/she also installs house trap and lateral
us examine how do they work.line. The main function of the house trap is to keep the
Drain Waste-Vent System and Gravitywaste and odors flowing out of the home, while the
Earlier galvanized caste iron was used in the pipinglateral line ties the house to the municipal sewer line.
system, but now-a-days PVC piping is generally used.This lateral line first goes into a sewer system down
PVC piping is much better than the galvanized castethe street, and then it collects through a main
iron, as the later one clogs much easier. This distributiondistribution line, and finally goes to a sewer processing
PVC piping system brings the water to the toilet bowlplant.
and the drain waste-vent system takes all the usedAir Admittance Vents
water and waste away from the home to the sewerAir admittance vents are fitted under the sink. It helps
or septic system.sewer gases from coming out while drawing a bit of
The functions of most sewer systems are based onair in from under the sink. This way, these vents save
gravity. That is the reason why everything goes down.money for you by reducing the amount of waste line
In this process, the wastewater runs down the drain,vent stacks that you run. Moreover, they also help in
enters the waste line, and finally leaves the bowl.reducing the possible number of penetrations through
Supply lines in the drainage system are fitted at fortythe roof.
or ninety degree angles. This drainage specificationOther Important Things
goes with the flow and helps the gravity of the sewer - The sewage lines coming into the house
system to move the wastewater.must be higher than where they go to connect to the
The Venting Systemcity sewer line. This is an essential requirement, as we
Venting system is a piping system and one of theknow that the sewage moves by gravity.
most important components of drainage. The venting - There must be at least 2%-3% fall in your
system consists of pipes. You must have noticedsewer system. However, it depends on the elevation
several pipes sticking up through the roofs of theof your home as well as the elevation of the city,
houses in your neighborhood. These pipes are thewhich is the location of the connection.
venting system. - The fall the drain waste-vent system that
This system is also an essential requirement by thecarries fluids through the sewage system must be at
building code, as it prevents the water to draw out ofleast 0.25 inch per foot.
the traps that are under sinks. Moreover, the other - There must be two-degree fall into the main
main function of this system is to allow gases toline for the lateral.
escape. It also helps wastewater to drain properly byHence, here we see what are the components of a
relieving air pressure.drain waste-vent system, and how do they work.