Bend the end of a pipe to a point?????

# Thread: Bend the end of a pipe to a point?????

1. Solderer
Join Date
Apr 2018
Posts
6

## Bend the end of a pipe to a point?????

I have a project coming up soon where we will be pulling 120' of 30" diameter pipe into the ground. Those of you who may be familiar with directional drilling know that you cant really get a pull head this big to attach to the pipe for the drill to pull. I have made custom pull heads before but for some reason the boss wants to bend the end of the pipe we are pulling into a point and attach a pulling eye on this one. I have no idea how to do the math and measurements on a round pipe to bend it into a point using four sides, or whatever number of sides necessary to make a point. I have seen in electrical forums where they spread the end of a conduit a bit, cut a wedge out, then bend it in on itself to form an almost perfect point. But I cant do that with a 30" diameter pipe, obviously. The bends have to allow me to close the end of the pipe completely after welding so that no drill mud can enter the end of the pipe. So just cutting for slits and bending is not an option since the corners at the bend will open up like tear drops and it will take five thousand rods to fill the holes. I have some ideas in my head but I have no idea how to do the math to make it work. Has anyone ever had to do a bend like this? I'm assuming the math on a 1" pipe is the same for a 1,000,000" pipe so whatever you got, I can use it. Thanks!

2. ## Re: Bend the end of a pipe to a point?????

You are looking to do an orange peel. (modified to make a long point)

The math of each of the petals, where the horizontal line crosses, is the circumference desired at the distance from the baseline.
You'll likely want to make the petals longer so you can go to a point instead of a dome.

You'll need more than 4 petals of course.

Last edited by MinnesotaDave; 04-10-2018 at 07:20 PM.

3. Solderer
Join Date
Apr 2018
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6

## Re: Bend the end of a pipe to a point?????

Thanks. That was extremely helpful. I think a dome would actually be better than a point in this case anyway. I just figured a point was easier but this looks like something I can pull off. I hope it doesn't take me three days to heat and bend though. 30" is a lot of pipe. And this looks a lot easier than what I was going to try to finagle.

Join Date
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Location
Western Washington
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## Re: Bend the end of a pipe to a point?????

Sorry I can't help you out with a mathematical method to do this... normally on similar projects I make cardboard templates and go from that A simple sawtooth pattern with at least 20 tabs is what I would aim for however... because of the curvature of the pipe you won't be able to 'bend' the 'tabs' that are left....well at least not without some sort of tearing or collateral bending elsewhere you didn't want... or using a whole lot of heat!!! by your post I am assuming he doesn't want a 'cap' that fastens to the end like we do in pipe bursting and ddrilling. You didn't mention schedule of pipe but I'm guessing it's wall is gonna be upwards of 1/2inch.... would be far simpler to cut profiles to make a point or semi sphere point and weld it up then weld it to the pipe.

With a 30 inch pipe diameter you're going to have a circumference of well over 100 inches so any tabs over 5-6 inches will still have about a half inch of roundness to them and make them a pain to bend uniformly... there are also a few other things that will be affected more depending on the schedule of pipe.

I see Dave beat me to it with a much better reply
Last edited by ronsii; 04-10-2018 at 07:36 PM.

5. WeldingWeb Journeyman
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6. ## Re: Bend the end of a pipe to a point?????

orange peel cap.

https://pipefitting.browntechnical.o...SABEgIr6fD_BwE

not sure if it will lay you out to 30" but will help give you an idea

7. Solderer
Join Date
Apr 2018
Posts
6

## Re: Bend the end of a pipe to a point?????

Originally Posted by ronsii
Sorry I can't help you out with a mathematical method to do this... normally on similar projects I make cardboard templates and go from that A simple sawtooth pattern with at least 20 tabs is what I would aim for however... because of the curvature of the pipe you won't be able to 'bend' the 'tabs' that are left....well at least not without some sort of tearing or collateral bending elsewhere you didn't want... or using a whole lot of heat!!! by your post I am assuming he doesn't want a 'cap' that fastens to the end like we do in pipe bursting and ddrilling. You didn't mention schedule of pipe but I'm guessing it's wall is gonna be upwards of 1/2inch.... would be far simpler to cut profiles to make a point or semi sphere point and weld it up then weld it to the pipe.

With a 30 inch pipe diameter you're going to have a circumference of well over 100 inches so any tabs over 5-6 inches will still have about a half inch of roundness to them and make them a pain to bend uniformly... there are also a few other things that will be affected more depending on the schedule of pipe.

I see Dave beat me to it with a much better reply
Yeah, I figured out the math from what Dave gave me and went from there. A little over 94 inches circumference (not factoring in the thickness because I don't know what kind of pipe it is yet and I'm assuming 30" is inside, not outside). I'm definitely not a pipe fitter. All my work has been on barges where everything is flat and ninety degrees. 20 tabs is crazy compared to what I was expecting after seeing Dave's reply. I was thinking 8 maybe, but yeah, the base would be around 11-12 inches and bending would be hard to do. The last time we pulled a pipe this big it was PVC and I DID make a cap for it. I'm not sure why he doesn't want a cap now. It was a flat head cap with a pull-eye and 45 degree cross member supports. I just put two holes through it and welded a 2" bar north to south and a 2" bar east to west all the way through to hold it on. We were pulling through rock though so I think flat was ok then because the mud flow was better and we didn't have to worry about it digging into the side of the bore.
Last edited by WillyStanker; 04-10-2018 at 09:38 PM.

8. ## Re: Bend the end of a pipe to a point?????

What about cap end and use square tube or pipe as a frame to make a cone. If that open frame would fill up then cut and tack plate to the frame. That's a lot of pipe to be pulling.

This might be similar to what you did after rereading your post.

9. ## Re: Bend the end of a pipe to a point?????

you could use a weld on concentric reducer, or two to get down to a manageable size.

10. ## Re: Bend the end of a pipe to a point?????

Originally Posted by propanehotrod
you could use a weld on concentric reducer, or two to get down to a manageable size.
good ideer! a 30x anything conc. would help make something that would flow well, as that should be engineered into the design already. flow characteristics i assume work inside the pipe as well as outside, for driving through stuff

11. ## Re: Bend the end of a pipe to a point?????

I was thinking possibly rolling one if you have access to a roller? The orange peel idea looks intriguing also. Are you going to cap the pipe before putting on the cone so no mud gets into the pipe and possibly only the cone? It would be easy to cut a circle out and put it on before the cone goes on. I've never pulled anything before but just throwing out some ideas. A plasma table would make short work cutting that stuff out.

12. WeldingWeb Foreman
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New Plymouth ID
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## Re: Bend the end of a pipe to a point?????

how many tons of force does pulling 30" take? I would be worried the orange peel would separate pulling from the center because of the flex if it snags at all, at least if its thin pipe, under 1/2 wall, and the amount of time orange peeling that would take. what about a 2" plate welded in the end, sub to that with guide/sled fins to keep from digging in.

13. Solderer
Join Date
Apr 2018
Posts
6

## Re: Bend the end of a pipe to a point?????

Im not worried about it anymore. I guess the boss man wants to let his nephew do it. Im pretty sure its 1/8" and its at least 40 tons or more pressure. Im assuming its a lot because the drill we are using is capable of pulling 80 tons and we arent using our other drill which makes me think it exceeds its limits. I kind of hope the end does come off because instead of shaping the end of the pipe, he wants to make the orange peel cap and weld it on. I am still welding the pipes together but Im not making the cap. I think his nephew should come weld the cap on so when it comes off, everyone will know whos fault it was. I need a new job ha.

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## Re: Bend the end of a pipe to a point?????

Well definitely get some pics if you can I for one would like to see how it gets done... or at least how it gets attempted

15. WeldingWeb Journeyman
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## Re: Bend the end of a pipe to a point?????

I laugh when threads like these pop up. I imagine kids sitting in Algebra and Geometry classes saying "this is stupid and I'm never going to use this stuff" LOL

16. ## Re: Bend the end of a pipe to a point?????

If you've never made an orange peel, I recommend folks make one anyway, maybe not quite that large. They are a lot of fun and good experience should the need ever arise. I made my first one for a post out of 3" pipe so it would have a smooth, rounded closed off top. I just cut the "ears" with an angle grinder and bent them over. Lot of fun to make.

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