Misconception first
Every lesson opens with the thing people actually get wrong on the job, then shows why it is wrong. Not the textbook order — the order you meet it in.
Interactive, not illustrated
Change a diameter, move a support, watch the result follow. The 3D models are built from an engineering rules engine, so what you see obeys the same sizing rules a real support does.
Every discipline, one project
A line size is a process decision, a stress problem, a rack load and a cost. 12 disciplines, taught as one job seen from every desk.
Free interactive tools
Open any of these right now. Nothing to install, no account, no trial.
◎ Piping Stress
DLF ExplorerInteractiveDLF StoryInteractiveFailure TheoriesInteractiveMohr's CircleInteractivePressure Stresses in a Pipe3D model
⊞ Piping Layout & Design
⬓ Static Equipment
❉ Rotating Equipment
Nozzle Loads → Casing Distortion → Misalignment3D modelCalculatorShaft Alignment & Thermal Growth3D modelCalculator
⌂ Civil & Structural
⚡ Electrical
◈ Instrumentation & Control
∿ Process
◩ Materials & Corrosion
⚒ Construction & Commissioning
▤ Project & Contracts
General
Free lessons
A sample across the disciplines. Read the whole thing — no paywall on this page.
- Anchor Flange — Design Fundamentals
- Dynamic Load Factor (DLF / DAF) — the Price of Suddenness
- Pipe Rack Load Path — and Why Friction Governs
- Settlement: Uniform vs Differential
- Flange Joint Integrity — Torque, Tension and the Gasket Window
- Hydrotest vs Pneumatic Test — the Stored Energy You Cannot See
- Cable Sizing — Ampacity, Volt Drop, Short-Circuit: Three Checks, and the Biggest Wins
- Hazardous Area Classification & Protection Concepts — Contain It, or Never Start It
- Control Valve Sizing & Valve Authority — Why a Bigger Cv Controls Worse
- Orifice Flow Measurement — the Square-Root Trap
- Corrosion Allowance — and the Four Things It Cannot Do
- CUI and Chloride SCC — Why Stainless Fails Fastest Under Wet Insulation
- Pump Suction Piping — NPSH and the Eccentric Reducer
- Plot Plan & the Real Cost of a Metre
- Line Sizing — Pressure Drop vs Velocity vs Cost
- Relief Scenarios — What Actually Sets the PSV
- The Cost-Influence Curve — Why "We'll Optimise It in Detailed Design" Is Already Too Late
- Float, the Critical Path, and Who Owns Delay
- Shaft Alignment & Thermal Growth — Why a Perfect Cold Alignment Is a Defect
- Machine Nozzle Allowables — API 610, NEMA SM-23, and the Conditional 2× Rule
- Nozzle Loads & Local Shell Flexibility — the Vessel is a Spring
- Saddles, Skirts and Differential Expansion — One Holds, One Lets Go
- Inside the Pump Plinth: Two Cages, One Box
- The Industry by the Numbers — Three Maps That Do Not Overlap
- Code, Standard, Specification, Recommended Practice — Four Words Nobody Defined For You
- How a Code Becomes Binding — and What You Do When Two of Them Disagree
- Who Writes What — ASME, API, ASTM, ISO, EN, and Why There Are Five of Them
- Free Bodies, Resolution and the Moment Arm
- The Section Property You Stopped Computing
- Units, Interpolation and the Digits You Don't Have
- Hydrogen — Why the Smallest Molecule Rewrites Material Selection and Leak-Tightness
- Onshore vs Offshore — Why the Currency Changes from Area to Weight, and Everything Follows
- Pipelines — Gathering, Cross-Country and Distribution Are Three Different Machines
- Cryogenic Piping from −162 °C to −253 °C — What Contraction Costs, and What Actually Changes at Liquid Hydrogen
- CCUS — Why Dense-Phase CO₂ Is a Phase-Behaviour Problem Before It Is a Pipeline
- What Crude Oil Actually Is — and Why the First Thing We Do Is Boil It
- The Energy Transition for an Engineer — What Transfers, What Is Genuinely New, and Where the Work Goes
- Upstream, Midstream, Downstream — Not Three Places, Three Business Models
- Refinery vs Petrochemical Plant — A Property Business and an Identity Business
- Excavation — A Trench Kills You Two Ways, and Only One of Them Is the Soil
- Hot Work — Controlling the Spark Is the Easy Half
- Isolation and Lockout/Tagout — Whose Lock, and Who Holds the Key
- The Permit to Work — Why the Form Is Not the Control
- Working at Height — Wearing a Harness Is Not Fall Protection
- Cranes and Lifting — What Actually Decides a Radius, and Why Capacity Falls Away From the Machine
- One Job, Every Desk — Tank to Pump
- Valves — Three Axes, Not Thirty Valves: How the Closure Member Moves Decides Everything Else
- PSA 7.6 — Spring Arrangements: Hung, Seated, From Below, Trapeze — the Unit Is Not the Support
- API 610 Pump Types — Overhung, Between-Bearings, Vertically Suspended: What the Shape Decides
- Heat Exchangers — Three Letters, and the Space in Front of Them
- PSA 10.1 — The Stress Report: What Goes In It, and How to Check Somebody Else's
- PSA 10.2 — The Stress Critical Line List, the Work Process, and the Discipline Interfaces
- PSA 10.3 — Site Checks: The Walkdown, Spring Hot/Cold Settings, and As-Built Validation
- PSA 10.4 — Failure Case Studies: What Actually Breaks, and Why It Is Almost Never the Code Stress
- PSA 3.1 — Load Types: Primary/Secondary, Static/Dynamic, Operating/Design
- PSA 3.2 — Thermal Cases: Design vs Operating Temperature, and Why One Case Is Never Enough
- PSA 3.3 — Building the Load Cases: the Template, and What the Software Will Not Write for You
- PSA 3.4 — Wind, Static Seismic and the Occasional Combination
- PSA 3.5 — Restrained vs Unrestrained, and the Hot-Sustained (Lift-Off) Check
- PSA 4.1 — Support Span: Deflection, Stress, and What the Table Hides
- PSA 4.2 — Support Hardware: Shoe, Guide, Line Stop, Trunnion, Dummy Leg
- PSA 4.3 — Restraint Types: Anchor, +Y, Guide, Limit Stop, Rotational, CNode
- PSA 4.4 — Friction & Gaps: Values, When to Use Them, and Why the Model Will Not Converge
- PSA 4.5 — Support Layout in Practice, and How to Optimise It
- PSA 5.1 — Flexibility from Geometry: L-bends, Z-bends and the Quick Manual Checks
- PSA 5.2 — Expansion Loop Design: Sizing, Location, and Loop vs Expansion Joint
- PSA 5.3 — Stress-Friendly Layout: What to Tell the Layout Team, and When
- PSA 6.1 — Why Equipment Governs: the Stiffness Hierarchy and Four Allowable Philosophies
- PSA 6.2 — Pumps: API 610 Table 5, Annex F, and Modelling a Pump System End to End
- PSA 6.3 — Compressors & Turbines: NEMA SM-23, API 617/612, and the Combined Check That Bites
- PSA 6.4 — Air Coolers (API 661) & Fired Heaters (API 560): Boxes That Leak and Coils That Walk
- PSA 6.5 — Vessels & Columns: WRC 107/537 and 297, Local Stress, Nozzle Flexibility, and When to Go FEA
- PSA 6.6 — Storage Tanks: API 650 Annex P, the Shell Bulge, and Settlement You Cannot Design Away
- PSA 6.7 — Worked Systems: a Column Circuit and an Exchanger Circuit, Modelled, Analysed, Qualified
- PSA 7.1 — Variable Spring Hangers: Selection, Hot/Cold Load, Travel and the 25 % Rule
- PSA 7.2 — Constant-Effort Springs: When, and How to Size One
- PSA 7.3 — Snubbers & Dynamic Restraints: Free When Slow, Rigid When Fast
- PSA 7.4 — Rigid Struts & Sway Braces: The Restraints That Are Not Quite Rigid
- PSA 7.5 — Expansion Joints & Bellows: Types, Pressure Thrust, EJMA and Tie Rods
- PSA 8.1 — Flange Leakage: Equivalent Pressure, NC-3658.3 and ASME VIII App. 2
- PSA 8.2 — Jacketed Piping: Core + Jacket, Spiders, and the Thermal Cases Nobody Runs
- PSA 8.3 — Buried Piping: Soil Springs, Virtual Anchor Length and the Transition
- PSA 8.4 — Non-Metallic Piping: GRP/FRP to ISO 14692, and HDPE
- PSA 8.5 — High-Pressure Piping: B31.3 Chapter IX, Thick Walls and Bore Fatigue
- PSA 9.1 — Dynamics Fundamentals: Natural Frequency, Mode Shapes, Damping and DLF
- PSA 9.2 — Modal Analysis: Mass Participation, Cutoff Frequency and the Mass You Left Out
- PSA 9.3 — Seismic Response Spectrum Analysis: When 0.15 g Becomes 0.5 g
- PSA 9.4 — Harmonic Analysis: Rotating and Reciprocating Machines as Tireless Excitation
- PSA 9.5 — PSV Reaction Forces: API 520/521, the DLF Method, and What to Model
- PSA 9.6 — Slug Flow and Water Hammer: Momentum on the Move, and How to Stop Paying for It
- PSA 9.7 — FIV and AIV Screening: The Energy Institute Method, and Reading Somebody Else's Study
- Confined Space Entry — "It Tested Safe This Morning"
- Line Breaking — Why "Depressurised" Is Not "Safe to Open"
- PSA 1.1 — Why Piping Stress Analysis?
- PSA 1.2 — Stress & Strain: the Language of the Course
- PSA 1.3 — Stresses in a Pressurised Pipe: Hoop, Longitudinal, Radial
- PSA 1.4 — Bending & Torsion of Pipe: Section Modulus and Combined Loading
- PSA 1.5 — Failure Theories: Rankine, Tresca, von Mises — and What the Codes Use
- PSA 1.6 — Mohr's Circle: Principal Stresses Without Tears
- PSA 2.1 — Stress Categories: Sustained, Displacement, Occasional
- PSA 2.2 — The B31.3 Code Stress Equations
- PSA 2.3 — Code Allowables: Sc, Sh, f, and S_A
- PSA 2.4 — SIFs & Flexibility Factors: Markl's Gift to Piping
- PSA 2.5 — Cold Spring, Self-Springing & Shakedown
- PSA 2.6 — The Code Map: B31.1 vs B31.3 vs B31.4 vs B31.8
- Piping Stress Analysis — Full Course Curriculum (EPiC Circle Course #1)
- Competency Shape Models — Growing from Piping Stress into EPC Leadership
The Circle
The tools and lessons are the half you can see. The other half is the Circle: a place to ask the question you cannot ask in a design review.
- Ask a question, tagged by discipline — answered by people doing the same work.
- Follow a thread and get told when it moves.
- Track what you have read, take the quizzes, keep your own notes.
The Circle is new. Early members shape what it becomes — that is the whole offer, and we would rather say so than invent a crowd.
Know why, not just what.
Signing in is free. It tracks what you have read, unlocks the quizzes and practice problems, and lets you ask a question in the Circle.
Join EPiC Circle →Educational teaching material — simplified and illustrative. Not for engineering
design use.
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