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Plumbing Repair Question: What Does the U-Shaped Pipe Under a Sink Do?

Plumbing Repair Question: What Does the U-Shaped Pipe Under a Sink Do?

The U-shaped pipe beneath kitchen and bathroom sinks is something that people expect to see but rarely stop to think about. “Why exactly does it have that shape? And why does it seem that every sink drain pipe has that same shape? It must serve a purpose.” And by then you’ve turned your thoughts to something more pressing.

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Yes, the U-shaped construction of sink drain pipes serves a very important purpose, and most of the time it performs its duties without you needing to worry about it. However, there are times with you’ll need an under the sink plumbing repair because this precaution built into your sinks has encountered trouble. When you have clogs or leaks in your sinks, call Wm. Henderson and we’ll provide you a fast and effective remedy.

The P-Trap Under Sink Plumbing Mechanism

The U-shaped bend in your drain pipe is called the p-trap. This pipe is also referred to as a trap. However, the term trap can refer to a number of plumbing fixtures that serve similar purposes. The name of this under the sink plumbing mechanism refers to the shape when viewed at an angle, as there was already a similar fixture called a U-bend.

How Does a P-Trap Operate?

The p-trap under sink plumbing pipe serves the function of capturing a small amount of water inside your drainpipes after the sink is used. This plug prevents sewer gases from coming up the wastewater line and out the sink. It also can trap small objects that fall down the sink, such as jewelry, making it easier to extract them. Many modern sinks have a valve along the bottom of the p-trap to allow easy access to anything that might have fallen into the sink.

P-Trap Parts & Components Infographic

To become familiar with the pipes and parts beneath your sink, view the infographic below. The infographic displays the sanitary pipe, p-trap, fixture, and ventilation pipe.

What Does the U-Shaped Pipe Under a Sink Do?

Causes of Clogged P-Trap Pipes

P-traps drain pipes can become trouble spots in some cases. Because they trap water, they can also trap debris inside the water, such as hair and soap scum. Unfortunately, a collection of dirt and debris will eventually cause the p-trap to clog. A plunger might eliminate the clog. If you are not able to remove food and contaminants from the sink with a pluger, you will probably need a plumber to come out to resolve the issue with your under sink plumbing. A licensed technician will disassemble the p-trap or utilize tools such as a drain snake or hydro-jetter to fix the issue.

The other common trouble with p-traps is when they dry up. If a sink doesn’t see frequent use, the water in the p-trap will evaporate and sewer odors will begin to escape from the drain. If you detect foul odors from around a sink, try running water through it to fill up the p-trap.

The p-trap will quietly do its job for you until something goes wrong with it—and then you’ll need expert plumbers to help. To receive plumbing repair assistance, contact Wm. Henderson Plumbing & Heating Inc. In addition, to fixture installation and repair, our team also offers other plumbing services such as sewer line replacement, garbage disposal repair, gas line installation, water heater replacement, and water line repair. Give us a call by phone at (484) 206-8594 to receive assistance.