As a fabricator of 40+ years, the last 30 or so as the workshop manager, I have constantly used trigonometry etc. to calculate cones, segmental bends and much more. Nowadays I am constantly asked by the fabricators to calculate developed lengths etc. to save them the time and effort of laying it out. I have developed this app so that they can do it for themselves and therefore save “MY TIME”.

With this Angled Branch app you can quickly develop the pattern for the branch pipe shape and the pattern for the shell hole shape. Enter the required details i.e. branch outside diameter, branch length, branch angle, shell outside diameter and if required branch thickness. Press/touch the develop button/icon and the branch and hole details are displayed ready for marking straight onto the material, the time saved is immeasurable when you consider, that, you do not need to draw the branch full size in two views and then transfer the development lines etc. to determine the true joint line, or work out the developed length pitches of the development lines. This app is a true time saver.


All of the branch pattern developments are for set on pipes and hole pattern developments are for the outside diameter of the set on pipe.

If you need to work to the inside diameter of the branch for the hole pattern, then you can develop the branch using the outside diameter of the branch and shell as normal and mark out the branch, then redevelop the hole using the inside diameter of the branch and the outside diameter of the shell. The inside of the branch will then be flush with the edge of the hole.

From the front screen select the type i.e. Paper wrap template or Mark on plate
A paper wrap pattern template is commonly used on preformed tube i.e. 10"nb etc, and wrapped round the tube and the pattern shape transferred to the material for cutting, whilst a plate pattern is marked directly onto the flat plate material before rolling and generally the pattern shape is cut after forming/rolling, although when using thin materials the pattern shape can be cut prior to forming/rolling as the material is easier to bend.

On the next screen enter the required dimensions etc. and press the develop button

The developed length of the branch circumference and pitch of the developing lines are displayed at the top of the results page with the true developed lengths shown below enabling you to mark out the pattern quickly and easily.

The grid line dimensions for the hole pattern are displayed below the hole pattern drawing, as well as the dimension between the shell center line and the branch center line i.e. Dim Z, this pattern can be marked out directly onto the outside of the rolled shell or, onto the flat plate before forming/rolling, it is advisable not to cut the hole prior to forming/rolling as the removal of the hole material could make it difficult to form/roll the material to the required shape/size.



Please Note! On the results screen, the drawings for the branch and hole patterns are representative only and show the general shape of the true patterns.

Thank you for purchasing this app, I hope that from your feedback/comments I will be able to add extra relevant features and amendments in future editions.