How Do You Measure for a Tee Fitting?

To measure for a tee fitting, you primarily need to determine the diameter of the pipes it will connect to. Here's a breakdown:

Measuring Pipe Diameter

The most common measurement needed for a tee fitting is the diameter of the connecting pipes.

For Male Thread Pipes:
- Wrap a string around the pipe.
- Mark where the string overlaps.
- Measure the length of the string up to the mark. This is the circumference.
- Divide the circumference by pi (approximately 3.14159) to get the diameter.
- You might need to convert decimal to fraction.
- Example: If the circumference is 6.28 inches, the diameter would be approximately 2 inches (6.28 / 3.14159 ≈ 2).

Tee fittings are typically specified by their connection sizes.

Reducing Tees: If the tee has a smaller outlet (or two) than the main run of pipe, it will be specified with those reduced sizes. Example: A 2 x 2 x 1 tee will have two 2-inch connections and one 1-inch connection.
Standard Tees: A tee where all the connections are of the same size is often simply described by that single size. Example: A 2-inch tee has all 2-inch connections.

Identify all connecting pipes: Determine the type of pipe and the threads needed (if any).
Measure diameters: Use the string method (for male threads) or a caliper if the pipe is exposed and accessible. You can also measure the inner diameter of a female threaded fitting directly.
Note the needed sizes: Record each measurement.
Specify Tee: Combine measurements to specify the tee with the correct fitting sizes. Example: 2-inch x 1-inch x 2-inch reducing tee.

Threads: Whether you are dealing with male or female pipe threads will affect the fitting needed for the connection. Ensure you measure correctly based on the type of thread.
Material: Ensure the tee fitting material is compatible with your piping system.
Inner or Outer Diameters: You typically need to measure the outer diameter (OD) of the pipe, but when you're measuring for a female thread, you're technically measuring the inner diameter of that fitting.
Accuracy: Double-check all measurements to ensure the correct fit.