sheet metal

First you need to understand the relationship in metalurlogy and the compounds of your pipe material. There are premade dending tools for most pipe up to 6" diameter.

Anything over 6", is usually made from the pipe manufacture. If you are using an extruded pipe, such as the type used in plumbing large quantities of fluid flow, oil, gas, sewage, it is to your best advantage to have the manufacture make the 90* bends for you. Thinwall pipe is only easy to bend and form if you have the proper molds and dyes to perform the function. 20" is a rather large circular area to bend and special equipement is used to bend such sizes. Large hydraulic press machines, radius sweep mold would actually cost more then $20K to fabricate, special incert material to help support the walls of the pipe from collapsing during the bend.

It is to your advantage, as a costing factor, to have the bended pipe made from the manufacture of the pipe. They have the special equipement for this type of function. During my time as a field engineer at several minning facilities, we always purchased the required 90*bends premade from our supplier. I would rather pay $400 for a 24" elbow over having to reinvent the wheel in any application.

Good luck on the hunt.

Maximo

Formula? What, you want me to do your homework for you? Ha!

If I were given the job, I would build a tool which would rotate around the outside of the pipe, and create a circular impression all around it. Then make another ring, and then another beside the first one. When I have 10 or 12 dented rings, the section of pipe will look like a bellows, and will be (compartively) easy to fill with sand, and bend to 90 degrees.

Your way will probably differ. My way would work.

Bends for 20in pipe are available from pipework distributors. There is no need to home-brew.

I don't think you can bend it. I thought this was about sheet metal.

You're going to have to cut the pipe at a 45 degree angle and reweld the pipe at 90 degrees.

As it is not possible to bend 20 " pipe to 90⁰ right angle by normal means, you can consider a 90⁰ fabricated bend with 4 piece or 3 pieces of 20 inch pipe. Apart from 90 ⁰ you can make even 60⁰ or 45⁰ also. This is similar to fabricated eccentric and concentric reducers of various sizes, where forgings are not available.

All the calculations for making above are available in " pipe fitter's and Pipe Welder's Handbooks".

Other option is big pipe bending machines specially made for bending pipes in cross country pipelines and manufactured by Caterpillar and similar Pipe Laying Companies. We have used up to 18 inches and feel 20 in. should be also available.

Sridhar.

can you provide the name of authors and publications of this book so that i can purchase it? please help me.

sajid

(A)

Data Book for

"Pipe Fitters and Pipe Welders"

By E H Williamson. Updated by CMJ Sutherland Associates

Building Services and Energy Consultants

Published by RUPA & Co. (civil Engineering) Rs. 20/-

(B)

"Pipe Fitters and Pipe Welders"

By Thomas W Frank land - Glencoe publishing co. Encino, California

Collier Macmillan Publishers, London.

In India by

ED Galgotia & sons

Technical, Scientific, Management & Medical Hand books

Postbox no.688

17B, Cannught Place

New Delhi - 110 001.

ph. 2321844 (old no. and would have changed by now)

Sridhar

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