What Is a P-Trap and How Does it Work?

In the world of plumbing, it can be hard to keep up with all of the different parts that make up your pipe system. One crucial piece of the puzzle that all homeowners should be aware of is the P-trap, as this U-shaped pipe plays a significant role in maintaining the integrity of your drainage system. In the past, plumbers may have installed a similar type of piping called an S-trap, but these pipes have since been deemed ineffective compared to P-traps.

In this article, we’ll go over what P-traps are, their essential functions,  and why they should always be used over S-traps. 

What Is a P-Trap?

P-traps can be found under most sinks, drains, and other basins, where they connect a sink or drain to a municipal sewer system or home septic tank. Typically, P-traps are made out of metal or PVC pipe, and when they’re installed, they resemble a horizontal letter P. 

The main function of P-traps is to block sewer gasses and odors from coming back up through your drain. By blocking these potentially hazardous gases, correctly installed P-traps ensure a clean and hygienic living or working space. 

What Is a P-trap Used For?

P-traps are primarily designed to help the overall functionality of your drainage system. Whether the P-trap is regulating airflow, preventing odors, or capturing debrism, it’s essential to your home’s plumbing system. Learn more about what P-traps do below:

• Odor Prevention: The way that P-traps are shaped causes a water seal that prevents the foul-smelling gasses that it blocks from entering your home. If your P-trap is not installed properly or functioning as it should, foul-smelling sewer gasses will leak into your living space. 
• Debris Capture: P-traps help capture debris and prevent it from entering your main drainage system. Substances like hair, soap scum, and other particles are all trapped by the curved section of a P-trap that helps prevents clogs in the system farther down the line. If you drop something valuable down the drain, like a wedding ring, the P-trap will usually catch it. Since P-traps are located under the sink, you can retrieve the valuable item far more simply than if it went farther down your drain.
• Airflow Regulation: The water seal created by the shape of P-traps helps prevent air from flowing back into the system. By stopping air from flowing in the wrong direction, it helps the continuation of proper function. 

Why You Shouldn’t Opt for an S-trap

S-traps were previously used instead of P-traps in some drainage systems. Over the years, however, S-traps have been recognized as ineffective and are actually even prohibited from being installed in new construction projects in the 2021 Uniform Plumbing Code. If you were considering installing an S-trap in your home, consider the following problems that can arise when they are used instead of P-traps.

• Siphonage Issues: S-traps can be prone to siphonage, which is a process where the water seal they create is broken due to rapid water flow. Because the water seal is compromised, sewer gas can easily flow back up through the drains and enter the home, creating a potentially hazardous and unpleasant environment. 
• Venting Problems: Due to how they are shaped, S-traps may experience venting issues, leading to slow drainage and gurgling sounds. Proper venting is essential in any plumbing system, as backups can cause pipes to burst and other catastrophes that could end up costing you a good deal of money.
• Compliance With Codes: As mentioned previously, S-traps are now in violation of building codes and plumbing regulations. If you are a business owner or homeowner getting your property inspected, you could run into problems if you have S-traps installed instead of P-traps. 

Choose Peter Levi Plumbing, Heating, Cooling and Drains for Plumbing Services in Northern California

If you're looking for P-trap repair or installation services in Novato, Vacaville, or the surrounding areas, turn to Peter Levi Plumbing, Heating, Cooling and Drains. Our qualified plumbers can take a look at your current drainage system and either repair your current P-trap or help you install a new one. We also recommend signing up for Lucky’s Comfort Club, which is an annual maintenance program that provides regular inspections and maintenance of your plumbing system to prevent issues from occurring in the first place. Additionally, our coupons make it easy to fit repairs and new equipment into your budget.

Learn more about our plumbing services today. If you have any questions or want to schedule an appointment, please fill out our online form or call us at 866-717-4613.