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How Sewer And Drain Lines Work

Many people have no more idea of how sewer and drain lines work than they do about space shuttle mechanics. But unlike space shuttle mechanics, you don’t have to be a rocket scientist to figure it out. Here is a quick explanation of what you see in your house every day, but probably didn’t understand.

I need air!

Ever notice a 2” pipe sticking out of the roof of a house? Maybe several? You might even know them as  “ventilation pipes” without realizing they are there, not to ventilate the house, but to allow air to flow freely behind the water as it drains. If not for the ventilation pipes, the water would drain slowly, if at all, because it would not be able to push the water out of the trap, the U-shaped bend in the drain that keeps sewer gases out of the house.

Why so many sizes?

In construction, a plumber service chooses piping sizes based on what and how much fluid and solids will be going down the drain. Bathroom sinks are the smallest, since they transport very small amounts of water and even less solids. Kitchen sinks, shower drains, and washing machine drains are larger because of both the volume of water they must drain and the amount of dirt or food they must transport. Toilet drains are the largest. They typically flow straight to the main house drain, in order to avoid as many clogging problems as possible. That is why in a multi-story building, the bathrooms are often in the same place on each floor.

Preventing Clogs

Just before the main sewer pipe leaves the house, there is typically a Y-shaped clean out, or inspection valve. It is this valve that allows plumbers to check whether a clog is within the household plumbing, or outside of the house, where special techniques will be required. As routine maintenance, you should have a plumber out to do a video sewer-line inspection in order to assess and perhaps prevent problems in your sewer system before it backs up into your house.

If you have questions about your sewer drains, don’t hesitate to call your San Diego plumber, My Plumber Heating & Cooling– Same Day Service Guaranteed*! 1-877-697-5862


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