Pi Day is March 14. This year you can help celebrate by answering the question at the bottom.
Pi is the constant ratio of a circle’s circumference to its diameter, no matter what size the circle is. This is useful knowledge when you work with water pipes or oil or gas pipelines, and you need to replace part of it. You can measure the circumference and divide by pi. But there’s an easier way to do that.
Let a Lufkin Diameter tape measure do it for you. You just wrap it around the pipe, and read the diameter. Mathematicians call pi an irrational number, since it goes on for an infinite number of decimal places, but using a diameter tape is a very rational and easy way to find the diameter of a pipe. To see a little video on How to measure the diameter of a pipe, just click here.
This time, we won’t get into the geometry theory of pi that we had in high school. The magic of a pipe diameter tape measure is its simplicity of use. Here are the 3 steps to find the diameter of a pipeline:
Clean the pipe surface. Soil and any other contamination, of course, will make the pipe seem bigger than it really is.
Wrap the diameter tape around it, with the diameter scale visible to you.
Simply read off the tape. This will be the diameter, even though the tape is wrapped around the circumference. That’s all!
Some things to watch for…..Some OD tapes (diameter tapes) are marked in 100ths of an inch. Some are marked in 64ths of an inch. On the 64ths of an inch tape, 32/64 would be 1/2″. 16/64 would be 1/4″. 24/64 would be 3/8″. For convenience, you can use a magic marker to mark some of these common, but confusing measurements.
A diameter tape measure can save you a lot of time and frustration when you want to find the OD (outside diameter) of a pipe, post, or tree. This special tape has the inch scale (or metric scale) stretched out by a factor of pi (3.14159). So, if you wrap it around the pipeline, you will not see the “circumference”. You will see its diameter. You don’t need to divide your answer by 3.14159.
After you get one, and learn how to use it, you will use one every week for the rest of your life.
You won’t believe how you ever got along without one.
To help you on this fun journey as a FDTU, let’s find out…
What is a diameter tape.
It is a measuring tape that, when you wrap it around the circumference of a round object (pipeline or tree), it reads the “diameter”. If you would use a regular tape measure, you would have to divide by pi (3.14159) to get the diameter.
How to use a diameter tape.
You simply wrap it around a pipe or shaft, or tree, and have the diameter scale face outward, so you can read it. Make sure you don’t use the other side, because it would give you the circumference.
What you will use it on from now on, to make your life easier.
If you need to replace a car heater hose, but you want to have the new hose on-hand before you remove the old hose, use your diameter tape to measure the diameter (and length) of the old hose. You can do the same routine when replacing plumbing.
My friend owns a marina. He never heard of a diameter tape. I gave him a diameter tape and told him what it was for. He was in the FDTU group, and now he uses this valuable diameter tape measure every day.
Are you in the FDTU Group? Now you know how a simple tape can make your life easier.
If you have to find the length of a pipe, that’s easy. But what about the outside diameter of a pipe? What if you can’t just measure the diameter at the end? What if the pipe doesn’t have its ends exposed. It is part of a piping system, or a pipeline. How can you fine the OD, or outside diameter?
Most people don’t use a pipe diameter measuring tape. The reason is not that they don’t need one. The reason is that they don’t know how powerful it is. They don’t know what it can do for them. Just ask the people who use one every day:
pipeline installers and repairmen
oil and gas rig workers
sport ball makers
They will tell you this: If you want to know the outside diameter of a pipe or any round object, just wrap the diameter tape around its circumference, and read the diameter on the tape. Simple. You don’t have to divide by pi. The best part of this: Even if the pipe is not perfectly round, the od diameter tape will give you the average outside diameter as if it were perfectly round.
The Pipe diameter tape measure is often misunderstood, and often unheard of. That’s because most people don’t need one. But if you understand what it can do, you would probably use one.
It’s too hard to use. False. All you do it wrap it around the pipe and read the diameter right off the tape.
It’s too bulky to carry in my pocket. False. Many are no bigger than 1 1/2 inches square, and 1/4 ” thick.
I can’t find any at the hardware store. False. Try an online store. They are out there.
It’s not accurate. False. The simple pocket Lufkin diameter tape is accurate to the 100th of an inch of diameter.
It’s no better than using a regular tape and dividing by pi. False. Due to the calibration and the location of the zero mark, it is made specifically to measure pipe diameters.
It is not useful for the everyday person. False. You can measure the diameter of a tree, a hose in your car or boat, your furnace pipe, or plumbing in your home. Want to find out the diameter of that water pipe in your basement, so you can replace it? And you don’t want to cut it to measure it? Use a Pipe diameter tape measure.
If you need to know the outside diameter of a pipeline, and don’t have an exposed end, this is how you do it. Please click here for a short 2 minute video on this easy task. Let the Lufkin diameter tape do the work for you. There’s no need to use a bulky caliper or micrometer. There is also no need to divide the circumference by pi. A simple pocket-sized diameter tape is all you need. Here is How to measure the diameter of a pipe.