Guides / Pro
Pipe joint
PROFishmouth for pipe on pipe, with a full-size template.
What it is for
A round pipe joining another, square or at an angle, possibly off-centre. The app makes the template you wrap around the branch pipe and the hole template for the main pipe.
Where to find it
Calculator → Pipe joint.
Step by step
Give both pipes
MAIN PIPE (runs through) and BRANCH PIPE (gets coped). Pick from the catalogue or type the outside diameter.
Give the angle
Under ANGLE BETWEEN THE PIPES: 90° is square. The app works from 20° to 90°.
Off-centre?
If the branch pipe is not in the middle, enter the offset under OFFSET FROM CENTRE.
Choose the fit
Weld-gap fit: the inside wall bears, and the outside leaves a gap for the weld by itself. Snug outside: you grind the inside yourself.
Print the template
"Templates as PDF (1:1)" makes full-size A4 pages. Cut out, wrap around the pipe, mark and grind away.
Worked example: Pipe 48.3 on 48.3, square
Two equal pipes, snug outside.
| What | Result |
|---|---|
| Template width (circumference) | 151.7 mm |
| Deepest cope | 24 mm |
How the app calculates
- Circumference = π × 48.3 = 151.7 mm: that is how wide the template is.
- For two equal pipes at 90°, the deepest cope is half the outside diameter: 24 mm.
Tips for the best result
- Large pipe? Turn on "Half template": print one half and flip it along the throat line. It saves pages.
- The thinner pipe is always the one you cope. If the branch pipe is bigger, swap them.
- Print at 100 %, not fit to page, or the full size will be off.
Questions
Why does the angle stop at 20°?
Below that the cope gets impractically long. The app then uses the nearest limit and tells you so.