Sink Drain Pipe Size Code

All the pipes that connect to the tailpiece including the p trap assembly.

Sink drain pipe size code.

Bathroom vanity with cooper sink. Compare the fixture to the minimum sizes of drainage pipe by fixture table. The last size is 4 inch drain pipe that can be connected to 160 units in horizontal stack and 240 units in vertical stack. This is the minimum size to use for building sewer or drain pipe that is connected to the toilet.

Horizontal drain pipes connecting the sink drains to the trap must have a minimum slope of 1 4 inch per foot toward the trap. According to most codes copper supply pipe must be supported every 6 feet galvanized or black steel pipe every 12 feet pvc or abs drainpipe every 4 feet and cast iron pipe every 5 feet. For instance the minimum pipe diameter for a washing machine drain is pipe with a 1 1 2 inch diameter. A single trap can service more than one sink but adjacent drains cannot be farther apart than 30 inches.

Some older sinks may have drains that connect to a 1 1 4 inch tailpiece but most modern drains have a 1 1 2 inch outlet. To be safe install more supports than are required. Tables of plumbing drain pipe vent pipe sizes critical distances to plumbing fixtures. Below our tables 1 and 2 summarize common plumbing code specifications for fixture venting and vent pipe sizes and distances that a plumbing fixture can be located horizontally from the vent stack.