cut pipes to weld a "T"

Look up tube mitering on google or go to these links and see the tube mitering download links ftp://ftp.ihpva.org/pub/software/index.html

Ben

I've just pissed away 1 1/2 hours trying to get something to work here. The first link needs a postscript printer - ain't got it.

The second link, tubemiter.exe prints out the paper copy of the tube miter fit to an 8 1/2 x 11 paper, not to scale.

Another link on down the page, winmiter.exe has the same problem. Maybe there's something I don't know about printer setup here????

The link talking about an excel spreadsheet feeding AutoCAD would be just GREAT, but the link don't point to it. Points to some page about building bicycles.

Anybody know of something else, or the old fashioned way with paper and a drafting machine?

Karl

The real old-fashioned way, Karl, is to clamp the pipes in a T and use a long piece of soapstone to scribe one off the other, then cut it, clean up the cut, reclamp, and scribe the other off the first, then make that cut, clean up, fit and weld. I've seen shipyard pipefitters do that hundreds of times.

Grant

Karl Townsend wrote:

Does this joint need to be capable of passing liquid or air? How much mechanical load should the joint support? It would appear that the pipe approaching the side of the other pipe requires a fishmouth cut. If no connection is required, the other pipe can be left as is. If liquid must flow, the other pipe will require a matching joint to receive the fishmouthed end.

I know how it's done and have to do it regularly as part of the 12 on 12 inverted branch test, which is a common welding test in the pipe field. But, it's pretty hard to describe, at least for me, your best bet is to buy one of two small books, "Blue Book of Fitters...Welders Pattern and Layout Manual" by H.G. Thorsness or "The Pipe Fitters and Pipe Welders Handbook" by Thomas W. Frankland. Both show the steps to lay out a branch as well as many other things. Or, you can buy store bought patterns, or, you can try one of the online sources mentioned tho you seem to not have had any luck there. Another alternative if you have time on your hands, is to just start whittling away until it fits.

regards, JTMcC.

I just ran your dimensions on Tubemiter. The units are mm, so you have to convert from inches to mm. The printout was only 1/2 the template, so you need to run it twice and paste them together. I didn't try it, but it looks about right.

I also ran your dimensions on Winmiter. Again, the printout was only 1/2 (in landscape mode) the template. But print and paste two copies and you have a whole template.

I did overlay the printouts from both programs, and they match very closely.

Another old fashioned way is to use something fairly stiff as some heavy gasket material to hold on the pipe in what you think is the right shape and mark it with soapstone. Cut with oxy/acet, see how much you missed it by and mark again using the guide. A piece of four or six inch wide flat belt a couple of feet long would work real well.

With six inch dia pipe, the deepest part ought to be 3 inches in from a straight cut end.

Dan

I would also suggest you ask at Sci.engr.joining.welding. There are a lot of pipe welders there.

Dan

On Mon, 03 Nov 2003 21:24:21 GMT, "Karl Townsend" brought forth from the murky depths:

Hold the end of one pipe on a piece of paper (or use a coin the same size if possible, and draw a circle. Fold the paper in half so the arcs line up and cut out the circle. Wrap that around the pipe, mark, cut, and grind to suit. Flop the cut piece over and weld it. Easy enough?

Go to a welding store and buy a "Wrap Around". There are different sizes. There are instructions and marks on it that allow you to cut out the desired shape you need to get a repeatable pattern. I believe you can even order one specific to your use from them.

Steve

Easy enough, but it won't work.

Your way, you'll get an arc (a half-circle, actually) with a chord length equal to the pipe diameter, and with the arcs tangent at 90 degrees to the chord.

The correct pattern will be an arc with a chord length of pi divided by twice the diameter, and with the arcs tangent at 45 degrees.

Instead, I'd make the 45 degree cuts on the end of the vertical piece first, and make a pattern from that. Or, butt the pieces together and scribe the joint.

John Martin

A wraparound won't give you the ordinals to cut a branch.

JTMcC.

Karl,

You can lay this out using a 6" red rubber ring gasket (the gasket without bolt holes) and a wrap-around or center finder attachment on your tri-square. If you happen to find one of the old asbestos ring gasket, that one works better.

I'll try to describe the procedure. If I do not make this clear or understandable, I can take pictures tomorrow and send them to you.

Draw a line length ways on the pipe. Using the wrap-around or center finder, find the opposite side and draw a line.

Mark a line thru the center of the gasket.

Now, take the gasket and lay it on the pipe with the center mark on the line and the outer ring of the gasket at the edge of the pipe. Wrap the gasket around the pipe and using soapstone, scribe around the gasket. Repeat this on the opposite side.

What you'll have is two arcs drawn on the pipe. For lack of a better way to describe it, these arcs would be the "lips" of the fishmouth.

Now, turn the pipe 1/4 turn from the "lips" and scribe the "corners" of the fish mouth using the gasket. Wrap the gasket around the pipe and align the outer ring with the two arcs from the "lips". Scribe this line on both sides. This is the "corners".

You may have to trim some for an exact fit but this will be very close to final fit. When you're happy with the fishmouth fit, lay it on the pipe you're gonna cut into and scribe your line.

Rule of thumb on this "junkyard welder" tip is to use the gasket size for the pipe size you'll be cutting into: 4" branch off 6" pipe, use

Let me know if you need further clarification on this. Once you do it a couple of times, it'll be easy. And, fun too.

Just cut the main straight-through pipe so that you take out a 90 degree "bite" from one side going in as far as its centre line.

Then cut the end of the branch pipe to a 90degree "V" to match the "bite" in the main pipe.

Fit together, clamp and weld!

ave.

Use Ghostscript - lets you do Postscript on an ordinary printer. Geoff

Thanks

I'll start with this for a ruff fit, and then use the soap stone scribe idea for a final fit.

Karl

On 04 Nov 2003 19:02:50 GMT, snipped-for-privacy@aol.com (JMartin957) brought forth from the murky depths:

Wasn't the OP asking for a tool handle? Did he ask for mil-spec welding info? "Why seek perfection for a bloody pipe/handle?" I ask in earnest.

P.S: I grant that your method would be much prettier.

-- Friends Don't Let Friends Eat Turkey and Drive --