A sink drain is made up of multiple components. Kitchen sinks have a strainer situated in the sink hole and sealed to the sink with a band of plumber’s putty. Beneath the sink, the strainer body attaches to the tailpiece. If there is a garbage disposal, it will fit directly into a specially designed strainer body. Most bathroom sinks do not have a strainer but have pop-up stoppers.
A rubber gasket, metal washer, and locknut or retainer secure the drain body to the sink from underneath. A straight tailpiece attaches to the strainer body. The tailpiece, the drain trap, and a threaded nipple at a tee in the drainpipe are connected by a slip-joint coupling. Waste water exits through the trap and down the vented drainpipe to the main stack. The main stack then carries the waste water away from the property.
