Kitchen Sink Drain Pipe Size

The kitchen drainpipe connects to the drain under the sink.

Kitchen sink drain pipe size.

Drains connect to either a 1 1 4 inch or 1 1 2 inch tail pipe. The horizontal pipes connect to the trap with a double wye tee which has two y shaped inlets and one outlet. Since the pipe is 1 1 2 inch in diameter kitchen drainpipes are also 1 1 2 inches in diameter. These drains like bathroom and kitchen drains use a p trap which is a j shaped pipe that connects to the main drain line.

However with vertical drain stack this drain pipe size can handle up to two units connection well too. For instance the minimum pipe diameter for a washing machine drain is pipe with a 1 1 2 inch diameter. All the pipes that connect to the tailpiece including the p trap assembly. Unlike drain pipe on the shower or tub that will be connected to two units this sink drain pipe will be connected to only one unit on the drain line.

A single trap can service more than one sink but adjacent drains cannot be farther apart than 30 inches. The drainpipe threads onto this pipe with a connector. Horizontal drain pipes connecting the sink drains to the trap must have a minimum slope of 1 4 inch per foot toward the trap. Compare the fixture to the minimum sizes of drainage pipe by fixture table.

Kitchen sink is commonly connected up to two units or three units for one with disposer.