SWBPIPE · The open manual

SWBPIPE

The Open Manual

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

Start with the fundamentals · Explore a worked case

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

Foreword

This manual teaches piping flexibility analysis and explains how SWBPIPE performs it. It covers the fundamentals, solver mechanics, model preparation and transfer to the program used for validation. It also gives verification cases, their reference calculations and the source. Readers can study, review and teach from this material.

Many piping analysis programs are proprietary. Their vendors document and verify them, but their source is not generally available to other readers. SWBPIPE publishes its source and selected verification cases. Part III identifies the mechanics and supported routes. Case records identify the inputs, reference evidence and execution path; a case result does not qualify every product route.

The program is young. The chapters and status of this edition describe source revision a72f994d89. The case records identify their own evidence basis. Historical records retain their earlier source pins; three current pressure cases include fresh comparisons from 12 October 2026. Read that page with statements marked Today to distinguish implemented behavior from the engineering method taught here. Nothing here is a design basis. SWBPIPE does not judge code compliance or vouch for its results. Work that needs validation is validated in the program your industry accepts.

Contentsii

Contents

  1. Status of this Editioniii
    1. A. Mechanics and result limits
    2. B. Models that cannot yet be built or solved
    3. C. Bounded and unfinished capabilities
  2. Part I. IntroductionI
    1. A. What flexibility analysis is for
    2. B. Where the beam model stops
    3. C. How the method grew
    4. D. The name: Shipman, Watts and Burrows
  3. Part II. Fundamentals of Piping FlexibilityII
    1. A. Thermal expansion and restraint
    2. B. Primary and secondary loads; pressure
    3. C. Load cases
    4. D. The displacement stress range
    5. E. Bends, SIFs and branch connections
    6. F. The elastic centre and the force method
    7. G. Cold spring; hot and cold reactions
    8. H. Supports and restraints in practice
    9. I. Spring and constant hangers
    10. J. Equipment nozzles and imposed movements
    11. K. Occasional loads; how results feed a code check
  4. Part III. The Method in SWBPIPEIII
    1. A. The 3D beam model
    2. B. Loads
    3. C. Supports
    4. D. Load cases and combinations
    5. E. Stress recovery
  5. Part IV. Modelling GuideIV
    1. A. Building a model
    2. B. Components
    3. C. Supports, hangers and nozzles
    4. D. Load cases for a typical job
    5. E. Code data you enter
    6. F. Checking a model
  6. Part V. Validation ElsewhereV
    1. A. Design here, validate there
    2. B. The export today
    3. C. What changes when you validate
  7. Part VI. VerificationVI
    1. A. System benchmarks · 4 cases
    2. B. Elements and loads · 14 cases
    3. C. Stress recovery · 15 cases
    4. D. Nonlinear supports · 6 cases
    5. E. Algorithm and software checks · 26 cases
    6. W. Withdrawn · 2 cases
    7. Still to come
    8. The planned program
  8. Part VII. Theoryin preparation
    1. The derivation of every equation in the solver, published chapter by chapter
  9. GlossaryG
    1. Practitioner’s terms, with their equivalents in other programs
  10. SourceMIT
    1. The solver, the program and the schemas
Human–agent teamsChirality

Working with agents

People and agents are building SWBPIPE together. The methods for that work are published at Chirality AI, the home of the human–agent manuals and workflows.

Start with the result you need, work from the relevant sources, and use additional roles when the task benefits from them. Agents carry authorized work through; people shape its purpose and decide what to rely on.

These links lead to the current editions. The manual index identifies their sources and editions.

From Part VI · VerificationVI–A4
Plane L-shaped pipe between anchor A below and anchor B at the right. The vertical leg is 3 meters; the quarter-circle elbow radius is 0.5 meter. The horizontal leg is 4 meters. The uniform temperature rise is 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 bends through a quarter circle and warms by 150 K. The force-method hand calculation is compared with a direct bend-element/frame-kernel benchmark. The recorded reactions agree to seven significant figures for the tested flexibility factors from 1 to 20. This comparison does not exercise the desktop or product-physics load-generation path. The case gives the exact factors, deviations and tolerances.

Part VI gives each case’s problem, inputs, reference calculation, recorded result, limitations and execution path. A recorded comparison is distinct from a new run. The command identifies the path to reproduce the case.

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 work its general method rests on.

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