PVC Pipe and Fittings Library

Pipes

The dimensions of the PVC pipes can be found here PVC_Pipe. Wikipedia on Nominal Pipe Size (NPS) [1],

We will use following guide line for position of a pipe: put one end (base) of the pipe onto the x-y plane. The center of the base has coordinate (0,0,0). The other end points to the positive direction of the z-axis.

Rationale: This is the same way FreeCAD places a new cylinder. We mimic the FreeCAD behavior for UI consistancy.

The default pipe length is 1ft. This is an arbitrary choice. When I use a macro, it will store the last length used by the user.

Elbows

Useful links: [2]

Simple general elbows

This is an intermediate solution. Here I do not follow particular NPT-Standards. Later I will translate the NPT-Parameters in these general dimensions.

To create general elbow with 6 Parameters:

• alpha - angle of the elbow.
• R1 - inner radius of the bending part.
• R2 - inner radius of the elbow.
• R3 - outer radius of the elbow parts.
• L1 - length of one part part of the elbow.
• L2 - length of the another part of the elbow.

I had problems to join all parts of the elbow in FreeCAD. The solution was to make the bent part a little bit smaller. Probably the problem was caused by having many common or coplanar faces of the parts. See [3].

90° - degree elbow

Described by 3 dimensions: size, G,H,M. Other dimensions are derived from NPS pipe-dimensions.

Notations

• O.D. - outer diameter.
• Average I.D. - average inner diameter (why average?). This dimension determines the size of the pipe.
• Min. Wall - thickness of the pipe wall.
• Schedule - determines (indirectly) the thickness of the wall.

Notes

"O.D." = "Average I.D."+2"Min. Wall"

Tees

Described by

G, G1, H, H1, L, M, Some other dimensions are taken from the pipe dimensions.

Gallery

• 

  SCH40 1/8" PVC pipe - size:5kb - FreeCAD -File:Pvc-pipe-nps-sch40-1d8.fcstd,

• 

  Elbow test file - size:5kb - FreeCAD -File:Pvc-elbow-test-60deg.fcstd,

• 

  Tee test file - size:24kb - FreeCAD -File:Pvc-tee-test.fcstd

Macros

Macros are now in a git repository [4].

Pipes

To create Pipes 40 and 80 Schedule PVC pipes File:Pvc-pipe-nps.fcmacro

Ellbows

(Experimental) Run File:Create-elbow.fcmacro with parameters G, H and M from a table.

Tee

Run File:Create-tee.fcmacro and select a part from the table

How to create a pipe macro

Steps to create GUI: The original instruction are taken from [[5]] but I (Ruslan) have problems with them. I adjusted them to FreeCAD.

1. Create with QT Designer a Dialog based on QDialog class. Save the name for example add-nps-pvc-pipe-dialog.ui
2. Convert add-nps-pvc-pipe-dialog.ui to python code running

   pyside-uic add-nps-pvc-pipe-dialog.ui -o pipe-dialog.py

   or call

   pyside-uic --indent=0 add-nps-pvc-pipe-dialog.ui -o pipe-dialog.py

   to use tabs as indention.

   If you use the FreeCAD macro editor, pay attention that the indention of pyside-uic and of the editor are the same.

3. Insert content of the methods setupUi(self, Dialog) and retranslateUi(self, Dialog) from pipe-dialog.py (How can I insert here a block of python code?) into your macro file.