The Kitchen Sink Plumbing
The three major parts of kitchen sink plumbing are the supply, sink, and drain. Each is explained here.
The water supply system begins with one hot and one cold water supply line protruding through the wall below the
sink. Escutcheons fit over the supply pipes at the wall to block air flow and pests. At the end of each supply line
is a stop valve. The cold stop may have two outlets if there is an icemaker to supply. The hot stop may also be
double to supply a dishwasher. Plastic or copper supply tubes carry water from the stop valves to the faucet.
Kitchen faucets, the final supply piece, come in a wide variety of types and styles. Single-handle faucets are
convenient, but double-handle faucets prevent inadvertent overuse of hot water. Sprayers may be mounted in the
faucet or separately. High-spout faucets facilitate filling tall containers. Faucets are generally sold with a
standard immovable aerator which can be replaced with one that swivels and has adjustable spray settings. A variety
of metal and enamel finishes is available to match any decor.
Kitchen sinks come in a wide variety of shapes, sizes, and materials. The most common type today is a
two-compartment stainless steel self-rimming sink. Other materials include porcelain on cast iron, natural stone,
and engineered composites. Single-compartment sinks are perfect for small kitchens, but they are often
inconvenient. Triple-compartment models have two normal basins and one smaller. There are even sinks designed for
corner installation. For installation purposes, there are three types of sinks--self-rimming, undercounter mount,
The final part of a kitchen sink plumbing system is the drain. The outlet of each compartment of the sink is
fitted with a basket strainer or garbage disposal. The simplest drain begins with a flared waste tube attached to
the basket strainer on a single-compartment sink. If there is a dishwasher, a waste tube with a wye inlet connects
the dishwasher drain to the system. A double-compartment sink has a "continuous waste" to combine drainage from
more than one outlet. The continuous waste attaches below the waste tubes or to the garbage disposal outlet. A trap
adapter fits onto the tailpiece of the continuous waste secured by a slip nut and nylon washer. Finally, a P-trap,
which traps a small amount of water to block sewer gases from entering the kitchen, joins the tailpiece to the