The plumbing drain trap under bathroom and kitchen sinks primary function is to retain water to block sewer gases from passing through the plumbing drain pipes into the air. The only differance between a bathroom sink trap and kitchen sink traps is the diameter of the pipe used for the trap. Kitchen sink traps and drain components associated with kitchen sinks are 1-1/2". Bathroom sink traps and drain components are 1-1/4". For both kitchen and bathroom sink drains the trap tail pieces, and extension tubes (except for the kitchen sink tail piece) are slip-joint compression connections.
The tools required for installing a trap is a pair of channel-lock pliers and plumbers pipe dope. Plumbing drain traps can rotate three inches to either side to align with the trap adapter. The trap adapter is the piece on the drain pipe sticking out of the wall the connect the trap to. There are two materials that plumbing drain traps and the other components are made of and these would be plastic and light gauge steel. I personally recommend using the steel traps and components because they come with rubber washers eliminating the need for the pipe dope between conections and are more durable.
Before removing the trap place a small bucket or equivalent under the trap to catch the water in the trap while you are removing the trap.
Plumbing Drain Trap Installation
Step1.
First insert a trap nut onto the drain tail piece with the threads facing down towards the trap, next install the plastic ferrule under the trap nut so the ferrule will be between the trap nut and the trap. Insert the trap over the drain tail piece and hand tighten the trap nut.
Step2.
The trap extension arm goes from the trap to the trap adapter. Attach the trap arm to the trap and cut to length if necessary. Insert a trap nut over the trap arm sliding it all the way to the mushroom flanged head of the arm with the threads facing the flange. Insert another trap nut over the trap arm with the threads facing out to attach the trap arm to the trap adapter, insert a plastic ferrule in front of the trap nut(will be between the trap nut and the trap adapter).
Step3.
Apply pipe dope to the outer rim of the slip joint connections on the trap that makes contact with the plastic ferrule. Apply to both ends of the trap and around the outer rim of the trap adapter.
Step4.
Insert the trap arm into the trap adapter and hand tighten the trap nut onto the trap adapter. Also hand tighten the trap nut connecting the trap arm and the trap.
Step5.
After hand tightening all the trap nuts, using channel-lock pliers turn the trap nuts another 1/8 of a turn being careful not to over tighten the trap nuts.
After making all the connections turn on the water and check around the drain and the trap for leaks. Some leaks are so small that it might take a few hours or a few days depending on the leak and how often the sink is used before the leak appears, for this i usully take a paper towel and leave under the drain. The next day if the paper towel shows drip spots there is a small leak which usully is not hard to find.
If you have a question about installing a plumbing drain trap or a question about another repair post it in the user feedback.
