Bending Conduit EMT With a Hand Bender Concentric Bends

[@erikdurfey5576]

Excellent presentation, thank you.

[@zaragla]

My husband, an electrician with 30 years of experience, said this is an excellent explanation. Thanks

[@yellowjacket7023]

I have an evaluation tomorrow over material I have not studied for over 18 months and I have unfortunately not bent any pipe in over 5 months ( including 3 months of being laid off). This saved me a lot of time going through my school books and notes to remember and more importantly, understand; I will still be going through those books to cement my grasp on all basics.

[@tommyfuller103z]

In practical terms where you would see concentric pipe bending being used would be industrial applications of where you would be running the main power circuit the big wires. The reason being if you were to use say 4 inch rigid pipe for the power feed and 1 inch conduit for the control feed. If we use the standard shoes for pipe bending. The 4-inch rigid pipe has a 20-inch radius. The 1 inch shoe on say a greenlee 555 Bender has a much smaller radius. And in many cases if you're going on the inside of a Bend. With a 1-inch being the first Bend than the 4-inch being the second Bend . Their center to center on the straight runs would be say 4 and 1/4 in center line to center line on a pipe rack between the two pipes. On the inside of the 1 inch Bend you would want to have a larger radius otherwise the standard Bend would end up hitting the 4 inch larger Bend. That would be an application of where you would use a segmented 90 bend on the smaller pipe.

[@asoteico9528]

God !!! First one see actually doing it !!!

[@daomowon7784]

Thanks Frank, was exactly what I needed.

[@donzmilky5961]

Thanks for sharing

[@LuminousLou]

Lot of real world applications this bend could be useful for

[@noel7777noel]

Even easier, Always bend in 10 segment bends, (no matter the radius). That will simplify the math and 10 segments always looks good anyways. Just times the radius you are looking for times .157. Them 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. 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 bending a 10" radius is marking the pipe 1.57" 10 times. But on very large radiuses you might want to add more bends. The 10 start to show.

[@theloneviking9145]

Thanks I’m going to try that today. I have to make a hoop with an 18 inch radius out of 1 inch conduit. Thank you for your tip.

[@noel7777noel]

@@theloneviking9145 it's times .157 times the radius, then mark the pipe 10 times that sum. I corrected my typo. I'm good at math, suck at grammar.

[@mbilal1170]

I know this is old so hopefully you're still around. I've never used concentric bends so I'm studying up on them. Do you just pick a radius ? If not how do you know what radius to use?

[@chrisgabriele2500]

Nice video.

[@BA-zs5zn]

How do you get the radius measurement? The 15 inches.

[@daidegoat]

I made it up for the video. I needed a measurement to begin with.

[@theloneviking9145]

He already had that piece of conduit bent that had the 12 inch radius. Then he wanted to have another piece of conduit 3 inches away from that first piece of conduit. So 12”+3” = 15 inches

[@xriver5867]

Hey, what about 3/4” conduit?

[@daidegoat]

this is 3/4 conduit

[@tommyfuller103z]

If I go back to 1996 working out of local 48 IBEW Portland Oregon. There was a steel mill in that city called Oregon steel. We ran parallel 3 inch metal conduit runs. The runs were several hundred feet long and ended up with 9 -90s on each of the parallel pipe runs. To satisfy code requirements there would be installed a c fitting. The radius is that we used 30 inch radius. The wire pulls went smooth as silk. We used 5° bends 18 bends for each 90. That was about the time they started coming out with digital protractors. The pipe bender we used greenlee 884 Bender. What you would find as far as spring back would be as the pipe progressively had more bends in it. The greater the springback. So let's say you're a 20° of been with for been so far you release the pressure at 20° and you find out you're only at 18 degrees. Obviously you need to bend that Bender that pipe to 22° release the pressure and then you find you're now at 20°. When you get to let's say 60° and you release the pressure and you find that well no right now I'm at 57 degrees obviously you put pressure on the pipe bringing it to 63° release the pressure then you'll see you're at 60°. Now you've made your 18th Bend you bring it to 90° you release the pressure. You now find you're at actually 86° so now you have to put pressure on the pipe and bend it to 94° release the pressure now it turns out to be 90. The spacing we use on those bends was 2 5/8 inches . Now remember these are centerline radiuses Bends. 30 inches multipled by 1.57= 47.1 inches. That is what's called developed length. Divide 47.1 inches by 18 Bends. There is your spacing in between Bends. 2 5/8".

[@daidegoat]

Bending larger conduit with a machine bender is far more complex than using a hand bender.

[@tommyfuller103z]

@@daidegoat The concept is the same! Math does not lie either. I have used a Greenlee Mechanical Benders the model 1800 better known as a Ratchet bender to do segmented bends while working a 1 inch pipe run for a baggage carousel at Bostons Logan Airport on the interior of the baggage handler doing 180-degree bends mounted on Unistrut rather than use metallic flexible conduit. 36_ 5 degree bends!

[@arnulfopernia]

excellent, the only videp I got like that. Do I need to make a 90 fold of a plasticbond pipe for underground, is the procedure similar? I mean the distance from the mark to where the bend actually occurs, do you think it affects?

[@daidegoat]

By plasticbond do you mean PVC coated rigid? It seems like you are using a machine bender. The technique will be similar in that case and distance from the mark to the bend will depend on the size of your conduit. Do your best to figure it out and then practice on a scrap piece. You'll be able to do it.

[@arnulfopernia]

@@daidegoat I was referring to metal conduit with plastic coating, something like anti-corrosion protection tape used for underground. the conduit is 2 ", something like that I thought but my doubt was because the distance of the marks is small compared to the point where the machine starts the bend. It will be time to test with one applying the procedure you show. Thank you.

[@nathansolomon9323]

Nice was that 2 3/8 for all size pipe

[@cheeese101100]

Great explanation, only question is does the multiplier 2 apply to all sizes of conduit?

[@daidegoat]

It's how the math works out. The multiplier for each angle, not just 2 for a 30 degree angle is the same regardless of the size of the conduit. It's almost like, at least for me, trying to explain why gravity works. I just know from experience that it does.

[@pcr442]

Hi Franck, I am doing a project with 1/2 inch conduit. I need a corner radius of 100 inches for a nice long arc (1/4 of a circle). I have used your formulas but it seems I need to add my marks closer together than what I'm coming up with. Any tips? By the way, my math works out to a bend every 7.85 inches. Is that enough to make a smooth arc?

[@daidegoat]

Good question. It could work out in half in conduit. You can also try breaking it into 15 bends of 6 degrees each - which you will have to guess a bit on. If you have some available scrap try making a 45 degree concentric and see how your math is working out. I taught myself a lot of conduit bending tricks out of necessity and experimentation. You can do the same.

[@pcr442]

@@daidegoat Thanks very much! conduit is pretty inexpensive so time to do some hands on learning! Great video. Keep 'em coming.

[@Mas0niq]

Hello, so where does the 15 come from?

[@daidegoat]

In an earlier video I showed how I filed a mark where the 10 degree line on the bender is. When the conduit touches that mark it is close to 15 degrees. My other videos show why 15 is a good angle to choose for some bends, especially the three point saddle.

[@a.ganzales8824]

R x 1.57!!!

[@kyledodge1241]

Maybe take a few more takes next time. This was hard to listen to