What’s the U-Shaped Pipe Under My Sink?

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Is your kitchen sink not draining properly? If so, contact our professionals at Pride Services for reliable Rockville Centre plumbing services. 

If you open the cabinetry under a bathroom or kitchen sink, you’ll see exposed plumbing that connects the sink’s drain to the plumbing system behind the wall. Have you ever thought about why that plumbing contains a U-shaped pipe? If so, you’re not alone. 

Our experienced plumbers at Pride Services are the top providers of Rockville’s plumbing maintenance services. Here, we offer a handy guide that explains the reason for this unique pipe shape and how it benefits your home. 

What Is the U-Shaped Pipe and its Purpose?

The U-shaped pipe might not seem like an essential plumbing structure, but it serves an important purpose. Though the line has a U shape, most plumbers refer to it as a P-trap because it resembles the letter P when you look at it from a different angle. It is part of the sink drainpipe that prevents sewage gas from decomposing wastewater deep within the plumbing from flowing back up through the drain and into your house. 

How Does the P-Trap Work?

The P-trap works using gravity to block gases from decomposed food and waste. As wastewater goes down the sink drain, it will reach the bend of the pipe that gives the plumbing mechanism its name. The pressure from the flowing water forces the water into a sanitary pipe for disposal. 

When the water stops running into the drain, a small amount of liquid will remain in the P-trap. As smelling gases move up the sanitary pipe, they will hit the water, which neutralizes the odor. The remaining gases escape through the vent pipe above the sanitary line. 

In other words, the water inside the P-trap is a plug that prevents your home from smelling foul. If you detect bad odors in your bathroom or kitchen that linger around the sink, the P-trap is likely too dry to block the sewer gas effectively. 

Another benefit of a P-trap is its ability to collect other items. For instance, if you drop a ring or another small item down the drain, it will likely remain inside the P-trap. Depending on your home’s plumbing system, you could remove the pipe and retrieve the item or get it by removing the valve at the bottom of the P-trap. 

How Does a P-Trap Develop Problems?

P-traps are beneficial, but they can trap more than water. Over time, the small reservoir inside the pipe can collect hair, soap scum, food particles, and other debris. Eventually, the solid materials will cause a clog. Plunging the sink could dislodge the blockage, but you might need to call a plumber to use specialized equipment like a drain snake or hydro-jetter if you can’t remove contaminants from the P-trap.

The water inside U-shaped pipes can also evaporate if you don’t flush water down the drain regularly. This is a common issue for guest bathrooms and vacation houses. Without water in the pipe, foul odors will escape the drain. 

If your sink smells bad, try running water down the drain for a minute or two. The water will refill the P-trap and neutralize the foul odor.

How Should You Care for the U-Shaped Pipe?

Good plumbing maintenance practices will help preserve the integrity of your P-trap and prevent smelly odors from escaping your sink drains. For instance, after cooking in the kitchen, dispose of grease, oil, and fat in the trash instead of pouring them down the drain. Oils and fats will solidify inside the pipe and create clogs as food particles and other material stick to the greasy material. 

In the bathroom, cover your sink and shower drains with caps. Though some hair, soap scum, and dead skin will flow down the drain, the cover will prevent most materials from going through the plumbing system, where they can accumulate and clog. 

If you notice your sinks or shower is draining slowly, don’t pour chemical drain cleaners into them. The acidic chemicals can eat away at your plumbing, causing more severe problems. Instead, contact a local plumber for efficient clog removal and drain cleaning. 

Turn to Pride Services for Drain Cleaning Services and More

When you need comprehensive residential and commercial plumbing services at competitive prices in Rockville Centre, NY, reach out to us at Pride Services. Our educated and trustworthy plumbers can handle any plumbing project, from water filtration services to drain cleaning and plumbing maintenance. Request an appointment or learn more about U-shaped pipes by calling our experts today at (516) 916-6894.

Published: Mar 20, 2023

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