How To Measure Pipe Fittings?

It’s critical to make sure you have the correct pipe size and pipe fitting measurements. If you don’t have the right measurements, it can cause unnecessary delays on the job.

The question you may be asking yourself now is: where do I start when measuring pipe and fittings? Well, we’ve put together a little guide on how to do that, along with some other key information.

what is pipe fitting?

Pipe Fittings are an important part of most plumbing projects. They allow you to connect pipes together and change the flow of the pipes.

They come in a variety of sizes and angles, allowing you to easily adjust the direction, speed, or flow rate of your pipes. This allows you to easily arrange your pipes to fit your space and needs.

Is pipe measured by inside or outside diameter?

Pipes are typically measured by their inside diameter (ID), also known as nominal diameter. The ID is the distance from one inside edge of the pipe to the opposite inside edge.

The outside diameter (OD) of a pipe is the diameter on the outside of the pipe, from one far edge to the other. 

Manufacturers use a sizing system that gives each size a name instead of a measurement. For example, what was once called 1-inch pipe is now called 25NB. The outside diameter for this size is always 33.7 mm, but the inside diameter will vary depending on the wall thickness.

The inside diameter of a pipe is important because it affects how much material the pipe can hold at one time, which can impact flow rates. 

Are pipe fittings measured from the inside or outside?

Measuring Outside Diameter of Pipe Fittings

The outside diameter (OD) is one of the most important measurements of a pipe fitting. Place the caliper around the widest part of the pipe fitting, making sure it’s perfectly straight. Take several measurements around the fitting to ensure accuracy. Clean pipe fittings before measuring, as dirt or corrosion can affect measurement accuracy.

Measuring Inside Diameter of Pipe Fittings

Measuring the inside diameter (ID) is critical to understanding flow capacity and ensuring a proper fit. Insert the caliper into the pipe fitting opening, being careful not to use force. Take measurements at several points to get an accurate reading. Note that some fittings may have different inside diameters at different points, especially in reducing fittings.

How to measure pipe fittings?

There are three simple steps you need to follow to ensure you get an accurate pipe size reading:

Check to see if the pipe has male threads, female threads, or no threads at all. Threads are grooves on the end of a pipe. Female threads are on the inside and male threads are on the outside.

Find the outside diameter of the male thread or no thread. The outside diameter is measured from one outside edge of the pipe to the other.

Measure the female diameter of the inside thread. This is the distance to the center of the pipe, but does not include the wall thickness of the pipe. Using a ruler or caliper, measure the distance from one inside edge to the other.