pipe layout question

Yesterday I ran across a picture in a book of a pipe which had been welded into a semi-spherical closed end. If you think of the top half of a tennis ball cut in half with a chop saw, then rotated 90° and again cut in half (so that the top half of the tennis ball was cut in quarters) and then the quarters were lifted straight up, if you just looked at that upper profile of the tennis ball and then if you layed out a proportional pattern on the end of a piece of pipe and cut away the material in between the "petals", then the tabs could be forged over into a semispherical shape and welded up to form the shape I saw yesterday.

I thought it looked cool. Naturally, being the curious type, I started thinking about how to lay it out on a pipe from first principles. Hoo, boy, that one is a tricky layout problem. Anyone know how to approach it?


Reply to
Grant Erwin
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It is a pretty straightforward development. If you can develop pipe intersections then it is not much different. Start with a side view of the profile and an end view. The pieces of orange peel or petals so to speak can be draw in both views then true distances extracted. You can decide on how many sections you want cut. Only four sections is crude. Six or even eight on a six inch pipe looks much better. If you have say six sections you only need one pattern. Split the circumference with lines then trace your marks onto the outside of the pipe. Once you have cut your petals take a rosebut and heat the petals. Don't rush hammering in the petals. Take it carefully heating at the base of the petals and bending them with your hammer gently and evenly. Work your way to the tips and as the sides close they should make contact supporting the shape. I was told that such an end will take the hammering effect of the fluid better than a flat plate closing off the end. Randy

Reply to
Randy Zimmerman

That's called an orange peel. The layout is described in detail in "The Pipe Fitter's and Pipe Welder's Handbook" by Thomas A. Frankland, also called the Frankland book by many pipe fitters. Looks like data is provided for 4 to 8 "arms" depending on the size of the pipe.

Gary Brady Austin, TX

Reply to
Gary Brady

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