Plumber Math: Offsets Part 3 - Rolling Offsets Using 45 Degree Fittings
HTML-код
- Опубликовано: 1 июл 2022
- A truly professional plumbers is going to know how to calculate a rolling offset. Being able to calculate for a rolling offset is often required on journeyman or master plumber tests as well. Without calculating, a plumber might eyeball or make a guess at how long the pipe should be, but this often results in material expenses as the pipe will be too long or too short and will have to be cut again.
There are a few steps involved with calculating a rolling offset. The math is based on the Pythagorean theorem. A rolling offset actually involves two triangles. First there is the triangle created by the offset and the rise. Then the diagonal of that triangle is used to find the diagonal where the pipe will go.
In this video Plumber-Tom explains and demonstrates how to calculate a rolling offset.
For better understanding of the International Plumbing Code and plumber math, be sure to purchase your copy of Plumber-Tom's book.
To purchase the book, go to one of the following links:
UpStryve
store.upstryve.com/products/j...
Amazon
www.amazon.com/Journeyman-Plu...
Thanks for watching! 
Развлечения
The best explanation for this is that,.
Thank you so much
Awesome! Glad this helps!
Thank you so much. Watched so many videos and this one makes the most sense
Awesome! Glad I could help!
From an apprentice Thank you you explained it In a way that clicked with me
Glad to hear it. Keep up the good work!
Thank you for Morocco
You’re welcome!
Thanks for the video and the lesson, Tom. I have been plumbing for almost four decades and have been a Master Plumber since 1994. In the type of plumbing I have done over these years, I have never really needed to use this math. I have always gone with the “eyeball”, hit-or-miss-and-recut-if-necessary method, but I am finding myself more and more needing to use the math you are teaching - it saves money! With the rolling offset, I understand the math, but it would be great if you could do a hands-on demonstration to show how this really works in the field. It would be interesting to see how you subtract the amount from the center of the offset to the base of the hub/end of pipe, and it would also be nice to see and know what the actual roll of the fitting is, as mentioned in the comment above. Is there any chance of you being able to do this? Thanks!
Thanks Bruce. I appreciate the suggestions. I have a long list of ideas for videos to produce. I will keep that in mind.
Good morning, Tom! This is totally unrelated to this video. You are very good at explaining math, so I’m wondering if, one day, you could produce a video on the math involved with hanging pipe - particularly with clevis hangers anchored into a concrete floor above - Unistrut not being an option. I know there are “cheat sheets” out there, but if you have a method that you use or recommend, it would be very interesting and helpful to see that method and math explained. My brain gets to the overload point sometimes when I am trying to calculate hanger heights, rod lengths, etc. on, say, for example, a run along a corridor with three different sizes of copper, all with different thicknesses of insulation, and one non-insulated SCH 40 steel pipe for gas - all parallel to each other.
To simplify, let’s say all of these pipes are on the same centerline from the floor. Of course, the hangers for the copper would have to be hung at their “temporary” height to allow the copper to rest in the saddle for roughing in, and enough rod must be left over to allow for the hanger to be dropped enough to allow for the future installation of the insulation, but the MATH! What is the math? What is your method? For the example I gave above, I could go through three or more notebook pages, adding, subtracting, scratching-out what I just tried to calculate because I forgot where I was in the calculation, then starting over again.
Laying-out and calculating hanger heights and rod lengths seems to be way too time-consuming for me, and I know that you know the answers to change that. If you would like an example of one I just did down a 180’ corridor, start from left to right with these four pipes, all parallel to each other with the same centers from the floor to the pipes: 1-1/4” copper hot return with 1” insulation, 2” hot copper supply with 2” insulation, 3” cold copper supply with 1” insulation, 3” SCH 40 steel gas with no insulation.
What do you think, Tom? Is this something you have an easy-to-remember mathematical solution for? Is this something you would be interested in producing a video for?
Hey Bruce. That is a good suggestion. I know exactly what you are dealing with. I did commercial construction work for quite a few years. I will put that on my list of videos to consider. Thanks!
Hi Tom, I just read your book. In book 2023 version page178, step 2 in all solve conflict with others: 7 x 0.414 = 2.89”the other is 2.98”.
apologies. looks like a typing error.
How would you still do this rolling offset if you used 2- 90 degree elbows on 45 degree angles?
You can do a rolling offset with two ninety degree elbows, but the math is different. You would just have to measure the offset between pipes, and subtract fitting allowances.
What about the actually roll in the rolling offset? Like how much you need to turn the bottom fitting to make the offset work. No one ever talks about that.
That varies for each scenario. I've found for me the easiest way to find that is to take the two 45s with the length of pipe Tom just taught to find and put them all together. For the rolling offset to work correctly those two 45s need be in line with each other. Usual fittings have marks on them to help find the different 45° angles. I'll look down the one fitting like I would a gun sight to make sure the fittings are in line. Once that is done you can take this pipe assembly and put it on the pipe where you want the offset to start. I'll take a tape measure out and measure the rise. If the math is done correctly this should land the offset right where you want it.
Hello Cody. Perhaps I need to do a follow up video demonstrating the offset. But to answer your question, the fittings in the offset need to be completely aligned in a flat plane. By that I mean, if the offset were laid on a flat surface, all the pipe and fittings would lay down evenly. If the fittings are turned out of square from each other, then the pipes will not go in a parallel direction before and after the offset. Does that make sense?
But nobody says that I order to use 45 angle you have to have the distance between the ages of the two pipes same with the center to center measure of the two pipes.
Thanks for watching
Why not just use the setback x 1.414 ?
Good question. Most of the time we are not given the setback or it is difficult to measure. But the offset and the rise are generally measurements we are given or that we can measure for ourselves. From the horizontal offset and the rise we can figure out the true offset which is equal to the setback and then multiply by 1.414 to get the diagonal.
How do you come out with 5.83 from 34?
Take the square root. On a calculator, type in 34 and hit the button that looks like a check mark. This will find the number which, when multiplied by itself, will equal 34. It comes out to be 5.83. Hope this helps.
Are you in Texas
Utah
CxC =?
"C x C" is a representation of c squared. I could not show a squared sign, so I typed it out as "C x C". But it means "C" multiplied by itself.
Believe on the Lord Jesus Christ and you will be saved
Agreed 👍
Im so lost
You can do this!
@@plumber-tom9470 im from Texas I go test in March
Do it with 90s
That is possible, but it does not require as much math. Just a measurement from center to center and subtract fitting allowances.
🤣 p̳r̳o̳m̳o̳s̳m̳
Thanks!