KBROWN,

You are using the term "sweeps". This is not a normal term used in piping.

Do you mean "elbow"?

And then do you mean a Long Radius 90 degree Elbow? Or a Short Radius 90 degree Elbow?

Or are you talking about 45 degree Elbows?

Have you explained all of this to your "Crew" (Students)?

Why do you want to fabricate an item when you should buy the item fabricated by a recognized vendor?

A ELBOW IS A STANDARD 90 OR 45, I AM WORKING WITH A SAY A 36" RADIUS SWEEP IN 8" TO 10" SCH 80 PIPE WITH SAY A 4' LEG AND A 8' LEG, I AM TRYING TO FIND A EASIER IN LINE WAY TO MEASURE FOR THE 36" RADIUS SWEEP, HOPE THAT MAKES MORE SENSE

Low tones low tones use the shift key...

Checkout post #6

the links are I think what you're asking for.

Standard Trig calculations should be able to help. I am still not exactly sure what you are looking for. If you need to know how much pipe your bend will use, you can calculate it with S=RΘ. S is the arc length, R is the radius of your arc, and Θ is the angle involved measured in radians. This formula only works with Radians, I will include a conversion calculation for you to convert from degrees to radians.

So, if your radius is 36 inches with 4 and 8 foot legs leading and leaving, all you need is the angle in radians. I will give an example with a 45° angle.

First compute the radians of 45°. You MUST have a calculator that can compute in radians!

45×∏⁄180 = .78539816......

So, now you have the angle in radians (I use a scientific calculator and save the entire number for accuracy, but round up to significant figures at the end)

S = R × Θ

S = 36" × .78539816

S = 28. 274334"

or about 28 inches of pipe in your bend.

Bending it is up to you, but you can use this equation to calculate how much pipe you will need for any radius of bend over any angle.

Drew

THANKS FOR THE INFO.

Semantics, gents.

90° Pipe Sweeps - US Plastic Corporation

Is this what you mean? Do you heat bend these on site, instead of buying them?

Manufactured butt-weld elbows are based on elbow center-line radius = pipe diameter (for short radius), or 1.5 x pipe diameter (for long radius), with an exception or two in small sizes. Other pipe bends, typically of even larger radius, are called "sweeps." They may be formed by segment bending, heat bending, or on a bending table, to any available or desired radius.

It is possible, using the law of cosines (vector dot product), to calculate the angle of bend between any two directions, say horizontal-plane north-northwest x vertical-plane 3:12 slope. If cold-bending, you overbend by about 2-3 degrees, because the pipe springs back when released.

Similarly, for any two successive bends in arbitrary directions, you can use the law of sines (vector cross product) to calculate how much to roll the pipe between the two bends. In 3D vector algebra, this can be expressed by determinants. (And if you thought--where would I ever use them things?....)

Once you get the hang of it, this makes for really efficient pipefitting, eliminating lots of elbows and welds. As far as I know, this might be a lost art, the way much of oxy-acetylene butt-welding has been supplanted by knobby socket-weld elbows. (Old-timer's rant, there.)

Draw a circle and divide it into quarters, do this on a template and they can use the template as go/no-go gage.

Make a template from a pipe an split it longitudinally, may the pipe be of sufficient size to slip over the work piece.

_{Don't bend around his head he won't see how you did it.}

The guys who make and repair steam boilers must have this down pat. Never have I seen so many bent pipes. Can you Imagine having to replace just one?

The next wizards are the electricians who make all that large conduit, one piece nesting into the next. Real artwork.

The only thing I can Imagine If I had to do one would be to first determine the angle of the bend, from one straight section to the next. A measurement from the center of the start of the first bend to the end would give me a chord. Then I would call a math major.

Bend allowance calculator

How to workout where to bend the tube?