A P-trap is a curved section of plumbing pipe located beneath sinks, tubs, and other fixtures. Its shape allows a small amount of water to remain in the pipe after use.
This water forms a seal that helps prevent sewer gases from entering the home. The trap also serves as a point where small debris may collect instead of moving further into the system.
Understanding the role of a P-trap helps explain why these components are present at most plumbing fixtures.
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