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What's a P-Trap For Anyway?

That curved pipe beneath your sink is called a P-trap. Because of its bend, it always contains a bit of water to prevent dangerous sewer gas from seeping into your home. It's also something of a catchall for anything you accidentally drop down your sink drain. Toilets and bathtubs have P-traps, too.

Purpose of the P-Trap Under Your Sink or Toilet

The P-trap has several important functions. Its U-shaped curve traps water, hence its name. This water prevents sewer gases from moving through the pipe, up the drain, and into your living spaces. Without the P-trap, your home would get smelly.

Another purpose of the P-trap is to catch debris. It will collect the hair, soap scum, fuzz, and other detritus that settle out of the wastewater you rinse or flush. The P-trap has a clean-out for removing this gunk, which may help if your sink drains slowly.

The P-trap also offers some peace of mind. If you’re washing your hands, and you accidentally drop your wedding or engagement ring down the sink, chances are very good that it will end up in the P-trap instead of your main sewer drain. (It may very well have saved your marriage.) The P-trap can catch pieces of jewelry, coins, and other small items that easily fit down the sink or toilet drain.

How to Retrieve an Item From the P-Trap

All hope is not lost if your necklace, earring, or ring went down the sink. Here's how to retrieve it:

  • Turn off the water to the faucet by turning the valves under the sink. This is a precautionary measure so that you don't inadvertently get soaked.
  • Clear out enough space under the sink. You're going to need some elbow room.
  • Put a bucket under the pipe. P-traps catch a lot of sludge, and the bucket will collect it.
  • Unscrew the cleanout nut with a pair of adjustable pliers and pull out the trap. The bucket will catch anything that falls out, including your ring.

This is a good time to clear the rest of the gunk out of the P-trap. Replace the drain plug, making sure to tighten all the connections you loosened. (You might even consider using thread seal tape.) Restore the fixture’s water supply, and wash your hands and tools.