The success of any project requires, among other things, having the right materials and supplies, and that they are of the right format. When it comes to plumbing pipes and fittings, finding the right size is key, but this can often lead to confusion.
Indeed, measuring the size of pipes and fittings is not as simple as you think. Here’s what you need to know about measuring plumbing fittings.
The difference between nominal and actual size
An element that confuses most people who have no idea water system, is the term “pipe size”. Rather than referring to the actual measurements of your pipe or fitting, pipe size refers to the nominal size or nominal diameter of the pipe. When you measure the pipe itself, you don’t take into account the inside and outside diameter. Also, these diameters can change depending on the thickness of the pipe material. For example, two different ¾-inch pipes may have different inside and outside diameters because they have different wall thicknesses. This is why nominal size is a key part of pipe and fitting sizing.
How to determine the measurement of the nominal pipe size?
A number of different factors and measurements can help you determine nominal pipe size, including outside diameter, threads per inch, or circumference. To get a truly accurate reading of the pipe size, you need to measure both the threads per inch and the outside diameter or inside diameter if it’s a female thread.
For male threads, be sure to measure the outside diameter at the widest point of the thread. For female threads, measure the inside diameter at the widest point of the thread. You can then use those measurements to find the correct size in the nominal pipe size conversion chart.
The best way to determine the nominal pipe size you need is to measure the outside diameter and convert it to nominal. To do this, wrap a piece of thread around the pipe (if male thread) and mark where the ends of the thread meet and measure. This will give you the scope. To get the diameter, divide the circumference by pi (3.14159).
If it is an internal thread, you would instead measure the inside diameter of the pipe or pipe fitting using a tape measure or ruler and use that measurement to determine the nominal diameter. . On the Internet you can find diagrams that allow you to easily transfer decimals to nominal diameters and vice versa, as well as the number of threads per inch.
How to find the right connection for your water pipe?
Finding the right hose connection can also be confusing. You need a fitting with a large enough inside diameter to fit around your pipe. Knowing the nominal size of your pipe will help you find the correct connections. When purchasing fittings, make your decision based on this nominal size, not the outside or inside diameter of the pipe.