Fabricating Pipe Fittings

Mr. Parthiban,

You wrote:"how they will cut 30deg elbow in site?"

The pipe fitter (in the shop or field) will use a metal saw or a cutting torch to trim a 90 degree fitting or a 45 degree fitting to the required 30 degrees. Then he (or she) will grind a weld bevel on the cut end.

It is a simple thing to do and it is done all the time. They should not need a detail to do it.

Is it permitted ? the flow may not be smooth

Here the sketch is with long elbow, with short elbow, it may be worse.

I am sorry "sb" but that is NOT the way to make a 30degree turn in a piping system using pipe fittings.

I don't know how you made the sketch so I can't show the right way.

Simple - ACAD

The fact is never heard about this modification- This type of cut/joint is done in large ducts but never heard on pipes. So let me learn from you (make a sketch, scan, paste )

Hi...are you speaking about smooth bends or mitered bends?

Anil Tiwari

In site, if you need to get an elbow with special angle like as 30^o, you can select 90^o elbow, then divide that elbow into 3 equally segments by using measuring tape, mark and piece of hard paper. Then start to divide the elbow into 3 segments by measuring any side and divide the measured length into 3 segments. The measuring sides shall be at least from inside radii, outside radii and from both sides of elbow and then link the markings until getting complete circuit around the elbow. By this procedure, the marking circular around the elbow must be perpendicular to the axis of the elbow at that section.

By this procedure you can get up to an elbow with 1^o, if you divided the 90^o elbow into 90 equally segments, and this procedure is familiar to all pipe fitters.

fitting to fitting welding is not permissible , a pipe shall be between fittings.

regards

khizer

Below is a site that sells books that provide details on how to create special angles on pipe.

http://www.thegangbox.com/c-154-pipefitterswelding.aspx

Cutting and modifying makers elbows be it long or short radius is a well used practice as is welding makers fitting to one another.

also manufacturing segmented or lobsterback bends from pipe is also a well used practice although not so much in this age and is a dying art.

I was taught both these methods of manufacturing bends during my apprenticeship and both are acceptable but it all depends on what medium is flowing through the pipework? ie steam has a scouring effect on the inside of the pipe and would eat through a lobsterback bend in no time at all.

and in todays world for speed cutting down a makers elbow is much faster