If you are installing a new sink or replacing an old one, you may need to connect a drain trap to it. The drain trap, which resembles a “J,” helps to filter wastewater as it exits the sink and into your plumbing system. It also prevents odors from rising up through the drain pipe, which is why it’s essential to make sure the connection is tight.
The drain trap itself is made of PVC or ABS. This type of plastic has a smooth surface, which is better for drainage than a rough-walled pipe. You can purchase a drain trap in kit form that contains the trap bend (the U-shaped part of the pipe), the trap arm and a tailpiece extension, or you can order it separately.
Typically, a sink drain kit includes the following parts: The waste pipe, the slip joint nuts and washers, and a trap bend that fits onto the waste pipe and a trap arm that extends into the branch drain opening in the wall. It’s a good idea to check your local plumbing code and make sure that you’re using the correct fittings, so don’t hesitate to ask for help if you’re not sure what’s involved in connecting a drain trap.
To install a new drain trap, start by removing the old drain. Position a bucket under the trap to catch any water that leaks from it. This will help you avoid making a mess as you remove the trap.
Next, use a pair of tongue-and-groove pliers to loosen the slip nuts holding the trap bend to the sink tailpiece and the trap arm. The trap bend should slide off fairly easily, though a bit of wiggling may be necessary.
After releasing the trap bend and trap arm, cut the waste pipe to the desired length with a hacksaw or pipe cutter. Then, fit a slip joint nut on the end of the waste pipe so the nut’s threads face down toward the adapter; add another nut and a washer that’s tapered toward the waste pipe; then screw the waste pipe onto the trap adapter. Repeat for the second waste pipe, adjusting the pipe as needed to line up the waste pipes without over-tightening the connections.
Once the connections are made, run water to test the connections for leaks. If you have a double-basin sink, run the water into both basins to verify that all the pipes are connected.
If you don’t have a bucket, you can place a piece of paper towel or rag under the trap to catch any leaks that might occur as you work on it. This will help you to keep the work area clean and prevent any spills from ending up on your clothes or carpeting.
A drain trap is a vital piece of your sink’s plumbing system that helps to keep your sink working properly. It’s designed to collect and filter a small amount of water as it exits the sink, and it seals against gases that could rise from your sewer system. A good drain trap should last for several years, so be sure to replace it when it needs to.