SWBPIPE · The open manual

SWBPIPE

The Open Manual

The mechanics, the evidence and the source of a program for piping flexibility and stress analysis

Published openly, 2026 Price $0.00 · MIT licence Chirality AI Ltd · Calgary, Alberta
Forewordi

Foreword

Everything behind an SWBPIPE result is published here: the mechanics the solver implements, the cases it is checked against with their hand calculations, the format for bringing your own code data, and the source itself. It is written to be read, checked and taught from.

For twenty years the programs engineers use to analyse piping have been closed. The results arrive; the reasoning stays inside. This manual goes the other way. Any number the program gives you can be traced to an element, an equation and a test, and every test can be run again on your own machine.

Nothing here is a design basis. SWBPIPE does not judge compliance with any code and does not vouch for its results; work that needs validation is validated in the solver your industry accepts. What the manual offers is understanding: how the answer was reached, and how you would check it.

Contentsii

Contents

  1. Part I. IntroductionI
    1. A. Why centerline analysis
    2. B. The name: Shipman, Watts and Burrows
  2. Part II. The MethodII
    1. A. The 3D frame model
    2. B. Elements, supports and loads
    3. C. Load cases and combinations
    4. D. Stress recovery
  3. Part III. Verification64 cases
    1. A. Mechanics · 21 cases
    2. B. Stress recovery · 15 cases
    3. C. Nonlinear supports · 28 cases
  4. Part IV. Rule PacksIV
    1. A. The format
    2. B. A template
    3. C. Building one from your own data
  5. Part V. The Data BoundaryV
    1. A. What ships, and what you supply
    2. B. What you may contribute
  6. Part VI. SourceMIT
    1. The solver, the program and the schemas
From Part III · VerificationIII–7
A plane L-shaped pipe between anchor A at the bottom and anchor B at the right: a 3 metre vertical leg, a quarter-circle elbow of 0.5 metre radius, and a 4 metre horizontal leg, under a uniform temperature rise of 150 kelvin. ANCHOR A ANCHOR B T1 T2 L1 = 3.0 m L2 = 4.0 m R = 0.5 m X Y ΔT = +150 K UNIFORM, NO PRESSURE, NO WEIGHT ELBOW FLEXIBILITY × k
Fig. 3.—Plane L-bend between two anchors

An expansion loop, solved twice.

A pipe between two anchors, bent through a quarter circle, warmed by 150 K. The reactions are worked by hand with the force method, then computed by the solver, and the two are compared to seven significant figures.

Every case in Part III is set out the same way: the problem, the inputs, the hand calculation, the solver’s result, the tolerance and the command to run it yourself.

Read the case →

SWBPIPE is named for W. H. Shipman, G. W. Watts and W. R. Burrows, credited in the 1941 Kellogg manual with the method this one continues.

The program: swbpipe.com · Made by Chirality AI Ltd · MIT licence