A Tee fitting is amongst the most common fittings and is available with all female thread sockets, all solvent weld sockets, or with opposed solvent weld sockets and a side outlet with female threads. It is a Tee in which the branch port is larger than the run ports.

Bull head Tees are defined as tee fittings where the "branch pipe" connection is of a larger diameter than the straight through "run" connections (Non-ANSI B16.9). In this, flow typically comes into the Tee via the "branch" pipe and the flow outlet is split between the two "run" connections. This is useful for supplying flow to smaller diameter piping in opposite directions without the need for reducers.

On a "bullhead tee" the side outlet is the largest socket on the tee and thus it looks somewhat like a bull's head. Bullhead Tees are best used in low pressure heating and air conditioning systems. They can be:

Some bullhead tee are made especially for ponds and are called "Riser Tees". These tees have a built in "cushion" in the bottom, where water fall before entering the dam pipe. The riser portion of the tee (top) being larger than the through pipe helps eliminate a vortex effect when the through pipe is full of water.

A grooved-end bullhead tee is also especially designed for use on fire protection systems. One can directly split the flow into two reduced branch lines without the use of concentric reducers.

In some cases, like in distribution of gas and liquid, a "special tee" is recommended over a standard bullhead tee as it has a tube inside the tee, which liquid passes through, and mixes well with the hot gas. By using this type of special tee, one need not depend upon the distributor to do this mixing.