Conduit Bending: Concentric Bends
HTML-код
- Опубликовано: 20 мар 2019
- #accesstopower #conduitbending #AccessElectric
accesstopower.com
In todays episode of AccessToPower we demonstrate how to calculate the developed length of 2 side by side conduits in order to make concentric bends. I used a 1" conduit and a 1-1/4" conduit side by side in this video to show how to mark and bend the conduits to have matching concentric bends. If you are running lots of different size conduits around a corner and need to make all the bends radius' match, then this is a technique you are going to want to learn and practice. This is also the exact method you would use if you were trying to bend a conduit around a tank. All you need to know is the radius of the tank and how far off the tank you are running your conduit. That will give you your radius and then you just need to find your developed length. Divide that developed length by the number of bends to go around the tank and start bending. electrical training electrical contractor
thank you! I feel way more confident in doing this on the job now. I've read how to do them, but I gained a lot from see how you calculated, measured and marked, and physically bent the segments.
Thank you so much for making this video so simple and easy to understand
great video. bending rigid is a skill to learn.
Beautiful video!
Thanks for the videos, great job explaining how to use trigonometry functions.👍
teaching this to 1st years thanks
Awesome
Great content man. Thank you for these videos.
Great video! I’m a smart ass know it all and even I learned something.
Thank u guys. Great channel keep going with this great content
I truly learned a lot from the video although I still have some questions concerning a little bit more detail on why he chose specific numbers maybe I just didn't 100% understand although it did help me with my concentric bends on a conveyor system that turned with the radius of 17 ft looks great but I'm not sure if the math is what I understand.
See my explanation.
I wish you were my journeyman/foreman as an apprentice.
I'm confused on how and why did you use the 17 marks. What determines how many marks you'll need to make?
9 Bends at 10 degrees or 18 bends at 5 degrees gives you a 90 degree bend.
Was wondering were you start your bend? The 1st line in the front of the hook? Or something else?
How did you decide where to start your 1st mark bend?
Thank you for your video
The first bend can be almost anywhere as long as there is enough room on the conduit to make the rest of the bends. It depends on where along the conduit you want the concentric bend
Hello,great class! I want to know if I can do that with a regular hand EMT bender and no with machine?
sure. the tequnique is the same, although keeping the pipe straight and level throughout the bend will be more difficult with a hand bender.
How did you know how many Mark's u needed to do the bend.since you mentioned 17 Mark's
@@jesusrodas9221 you still don't divide by 18, though? This ugly manuel is screwing with me
And since its really 1.8470588, repeating 18 times at 1.875 , (.0279, ) won't screw you?
Fantastic information. Where would I use this as opposed to regular 90s
Luke Strange. In an industrial environment when you’re running conduit along conveyors, or around large tanks, this technique comes in handy. You can make your conduit look great as it goes around a non-standard sized radius
Or Say you have an exposed rack and it has to look perfect you have an 1 1/4 inside a 3/4. You can use this to match the radius of the 3/4 to the larger inside pipes
Would this same method work to make a concentric 3 point saddle, like to go around a circular pillar?
I need to bend a 48 inch circle (hoop) for a project..would the formula be the same
How do I find the center of Shoe on my side winder?
Radius x 1.57 / ( divided ) # of shots ( 18 shots at 5 degree, 15 at 6, etc ... )
Thank You, Sir. So what's best for 3" emt ???
your going to need a hydraulic bender for 3 inch EMT. but the technique should remain the same as far as making multiple smaller incremental bends that total 90 degees.
coupling style angles
How do I find my numbers for 10 ft stick of conduit? My circumference is 441 ft
How do you determine the radius you need for the bend? How would i know what my radius should be?
You need to find the radius of the tank or conveyor or whatever you are going around plus or minus any supports.
Quick question to how I would find my radius I have to bend 4 3/4 imc pipes around a conveyor tomorrow and I am trying go prepared with a game plan and make it come out nice
Samuel Moreno
An easy way to find the radius of the 90 on the conveyor is to use two tape measures. Measure from one one end of the radius with one tape measure and from the other end of the radius with the second tape measure. Cross both tapes at a 90 degree angle. The tape measures should be an equal measurement when they cross. This is your radius. Don’t forget to account for your support dimensions. Hope this helps.
@@AccessToPower where did you come up with 17 as a number for your markings?
This would be done on the outside of the 90? Correct?
Ive had problems for years now. Decr every time i do segment 90s it doesn't look some at all. Im using the greenlee 881 and 854dx by the way. I mean the bend looks smooth. My only issue is that on the outside portion of the bend you can see indentations of the hook or saddle digging into the conduit. Is this natural or am i doing something wrong?
Put duct seal on the shoe. Sounds strange but it seems to soften the indentations. Nowhere near as noticeable.
The second conduit will, I presume, run outside of the first, therefore it needs a greater radius to do so (think of two circles - the bigger one, on the outside, necessarily has the larger radius). He chose 23" to push the conduits apart by 3" center to center, which should place about 1/2" gap between them when in place.
@blockededited8280: Thanks for the input. A 1/2" gap would be tight but I get your point. On Unistrut, Kindorf or B-line strut the straps or hold down clamps for pipe on trapeze hanger require some spacing for strap bolt and nut, and of course on larger pipe you need adequate spacing for large thick locknuts in panels or JB (junction box). Retired now, one of the contractors I worked for did hospitals and telephone buildings especially retrofit or upgrades to existing buildings. Probably 90% of all piping was with Rigid conduit. Rigid has a "spring back", the amount depending on which lot or batch along with size of pipe, temperature of pipe metal and changes constantly, ex: you may bend 8 deg then release pressure on bender then conduit may spring back to 5 deg. You can compensate by overbending and check each piece. This shop had guys who had worked at bending tables bending for entire crews and knew their pipe bending. Most places we were not allowed to use split coupling, Erickson fitting or short nipple to enter junction box, panels or switch gear. Your measurements had to be dead on. All pipes in a panel had a bond bushing with a unbroken copper ground wire connecting all bushings. The main water pipe coming into the building, we had to use large grounding clamps with two lugs on each clamp on each side of the water meter and jumper the meter with parallel runs of 750 MCM wire so if the meter was pulled this would not interrupt the ground, this in addition to driving ground rods around the building then Cad welding the rods to metal connecting jumpers in shallow ditch, " WHEW !!" 🤢go inside the telephone building, take a 90 lbs jackhammer, jackhammer the concrete off the face of a vertical I-Beam, get down to the I-Beam, then drill and tap the thick I-Beam then bolt a solid copper plate to I-Beam for equipment grounds. Telephone Co. was paranoid concerning grounding, many contractors wouldn't bid them they were so strict. I finally got into electrical control work on production machinery, thank GOD !! and said goodby to construction, remodeling and mental anguish.
To have all stub ups the same height, what method would be needed?
Cut to fit lol
I'm assuming your 20" and 23" radiui came from your pipe spacing plus width of pipe (right?) How would you know the radius of your first pipe (smallest radius) is that just the take up of the bender (1 1/4 is 16 3/8?)
You need to know the centerline bending radius of the object or pipe you are trying to follow.
Take up is related to developed length huh.
Great video but how did you determine at what degree to make your first bend
hi lssecodyj. I used 30 degrees for both angles. this was just arbitrary. you can use any angle you would like. the thing to keep in mind though is that whatever angle you use will have its length cosecant which is the multiple for the distance between your bends.
@@AccessToPower pardon sir I think it is 90°÷18=5° per bend.
@@AccessToPower I have a 4 inch factory elbow..just a regular 90° I have a 2" that I I have to follow around the outside of the 4"
How to I find the radius of an existing bend ?
Then how can I match it ?
@@brnrxn is there a chart ?
Andres Badel , you can try something like this www.pavingexpert.com/images/animations/ring_radius_tape.gif
Why did you use 20” x 1.57 the first time and then switch to 23”x 1.57 for the second pipe ?
The conduits are 3" center to center apart from one another. This causes the radius of the outer conduit to be 3" greater than the innermost conduit.
@@AccessToPower how did you get the radius?
How did you come with the spacing between the gaps and the degrees
This is what is called Long Shot.
Even easier, Always bend in 10 segments bend, (no matter the radius). That with simplify the math and 10 segments always looks good anyways. Just times the radius you are looking for times .157. Then mark the pipe ten times that sum. Done.
.157 came from consolidating of all the other numbers that never change. It's dropping the unnecessary repetition to make you go faster.
Also the use of 10 makes the math easier to do in your head. Just move the decimal place over one. Makes you even faster.
Smoking a math test in impossible speeds. So a 10" radius is marking the pipe 1.57" 10 times.
Are the number of shots up to me?
Why automatically divide it by 17?
How did you get 17?
Good thing you’ll never have to do these bends lol at least I haven’t
I'm willing to bet you are a commercial hand. In industrial you make them often, too often 😓
@@joseofno under which application might I need to do my 90s this way? I am a commercial electrician for the most part, but I have done some heavy and light industrial, i.e., rigid, IMC, and I never had to do my 90s this way.
ryan215553 unlicensed? Typical.
If you need to go around a large tank or cylindrical obstruction then segmented bends are definitely needed. As previously stated, it's more used in industrial work. I.E. Refineries, power plants
ryan215553 You would typically need these bends around tanks and vessels , we do them at the refinery quite often
Developed length = arc length
And here I thought he was going to do it manually with a bender.
Making it easier s not a problem why don’t you show them how to measure for a concentric bend in the field
What kinda benders, hickey, not regular hand bender.. Didn't even show us (You) bending it. WTH...
These are segmented bends not concentric