What is a P-trap?
A P-trap is the curved section of drain pipe beneath a sink that retains standing water to create a seal preventing sewer gas from entering the building.
The P-trap is the U-shaped or curved drain pipe you find directly beneath kitchen and bathroom sinks. Water flows from your drain into this pipe and pools there, creating a water seal. That seal is what stops sewer gases and odors from backing up through your plumbing into your home.
The name comes from its shape, which resembles the letter P when viewed from the side. The standing water inside the trap stays in place because of the pipe's geometry, even as water drains away. If you ever notice bad smells coming from a drain in an Aiken home, a dried-out P-trap (often from a fixture not being used for weeks) is often the culprit.
Beyond odor control, P-traps also catch small debris and objects that might otherwise clog deeper lines. They are standard in every home's plumbing system and come in different materials, copper, PVC, and chrome-plated brass being most common. If a P-trap leaks or becomes blocked, you'll see pooling water under the sink or slow drainage. Professionals handling drain cleaning regularly clear sediment buildup from traps to keep them functioning properly.