Standard Kitchen Sink Drain Pipe Size

The standard size and setting.

Standard kitchen sink drain pipe size.

However most of the bathroom sinks use 1 inch drain pipe. The 1 2 inch supply pipes that come to the sink each terminate with a shutoff valve and this valve is one of the two factors that determine the connector size on the faucet hose. This size is precisely the diameter of the pipe instead of the length. Every state may have different code on plumbing and it may affect the required size of the bathroom sink pipe.

A 2 inch sink strainer fits the standard bar sink drain. These drains like bathroom and kitchen drains use a p trap which is a j shaped pipe that connects to the main drain line. The main sewer pipe leading to the septic tank or public sewer is usually 4 inches. When installing a new kitchen sink drain or repairing an old leaking one you need a particular size drainpipe.

A standard rule of thumb is that sewer pipes leading away from a toilet are 3 inches in diameter. It provides the right amount of flow to drain a kitchen sink during heavy use. Drains connect to either a 1 1 4 inch or 1 1 2 inch tail pipe. Since all kitchens use this size of pipe it is best to stick with it during any repair.

The inlet must match the supply pipe and it can be a 1 2 inch female pipe thread fpt connector for galvanized pipes a 1 2 inch compression or sweat connector for. This pipe is the standard size for all kitchen sinks.