Equal Tees vs Reducing Tees: When to Use Each Type

The Role of Tees in Piping Networks

Tees create branch connections in a piping system, allowing flow to split or combine. The two main categories are equal tees and reducing tees. Choosing between them depends on the branch line size and flow requirements.

Equal Tees: Same Size All Ends

An equal tee has the same nominal size on the run and the branch. It is used when the branch line carries the same flow rate and pressure as the main line. Equal tees are common in distribution systems, process manifolds, and header piping where multiple identical outlets are needed.

Reducing Tees: Smaller Branch

A reducing tee has a branch smaller than the run. It allows a smaller branch line to take off from a larger main header. This is typical when a small instrument line, sample point, or auxiliary connection is needed from a large main pipe. The branch size is specified as a reduction from the run, such as 4 by 2 inches.

Flow Considerations

Reducing tees create a gradual transition from the large main to the small branch, which reduces turbulence and erosion at the branch connection. For low-flow branch takeoffs, a reducing tee is more efficient than welding on a small nozzle to a large pipe.

Specification Tips

Always specify the run size first, then the branch size. For example, a reducing tee with a 6-inch run and a 3-inch branch is written as 6 x 6 x 3. Confirm the pressure rating and material grade match the main line.