Features · ทุกความสามารถ

junctiondemanddraw-offteenode

Junctions & demands

Tee networks together at Junction nodes and pull flow out with node demands to model draw-off points. End-of-branch draws are best modelled as Assign Flowrate so the demand is preserved on load.

pumpcompressorpump curveNPSHvariable speedsystem curveoperating point

Pumps & compressors

Place a Pump (with a real head-vs-flow curve, variable-speed ratio, and NPSH margin) or a Compressor on the network. Suction and discharge pipe friction are counted correctly via node-splitting, so the operating point and system curve are physical.

control valveisolation valvecheck valveCvKvnon-return valve

Control, isolation & check valves

Model a Control Valve (Cv/Kv setpoint), an Isolation Valve, or a Check Valve that latches on reverse flow. Valve nodes split into flanges so the pressure drop lands on the right side of the device.

relief valveorificeorifice platebursting diskrupture diskknown resistancerestriction

Relief & flow-restriction devices

Add a Relief Valve, an Orifice / Orifice Plate, a Bursting Disk, or a Known Resistance element to set pressure limits and trim flow. Handy for pressure-let-down, protection sizing, and matching a measured resistance.

sprinklerair valvevacuum valvesurge relief valvesurge tankair chamber

Fire & surge devices

Drop Sprinkler heads, Air / Vacuum Valves, Surge Relief Valves, and Surge Tanks to model fire-protection and surge-mitigation hardware directly in the network.

pipefittingminor lossroughnesselevationscheduleK factor

Pipes, fittings & materials

Every pipe carries diameter, length, roughness, elevation, and a minor-loss (K / equivalent-length) allowance from a standard material and schedule library. Elevation drives the static head so risers and drops read correctly.

Model Builder → pipe properties

Steam-trap & heat-exchanger nodes

Model process equipment inline: a Heat Exchanger node from the palette with its own in-network sizing tab, and a Steam Trap node — reached by changing a node’s type or loading an example, not from the palette — with dedicated assist logic, distinct from the standalone equipment calculators.

heat exchangersteam trapprocess equipmentHXcondensateinline sizing

Model Builder → node palette → Heat Exchanger

Relatedin-builder sizing tabs

System fluid & Fluid Editor

Set one system working fluid as the single source of truth and override it per-node only where you need to. The Database Fluid Editor picks from a 1,000+ fluid database (the same FDB the calculators use) and applies instantly.

fluidFDBfluid databaseworking fluidoverrideinheritsystem fluid

Model Builder → Database → Fluid Editor

Project settings & conditions

Set friction model, fluid mode, ambient/thermal conditions, and special modes (gas, slurry, flare header) in one Project Settings panel that governs the whole solve.

project settingsconditionsfriction modelfluid modeconfiguration

Model Builder → Project Settings

Examples library

Load a ready-made example network — cooling-water systems, EPANET benchmarks, two-phase FluidFlow cases, fire loops, flare headers, and more — from the builder Toolbar’s Load-example menu (Validation / Archive / Tutorials / Multi-Fluid sets, roughly 80 networks wired) to learn the tool or start from a working model.

examplestemplatesEPANET benchmarkstarter modelsdemo networks

Model Builder → Toolbar → Load example

Model check & validation

Before solving, the builder validates the graph (dangling nodes, missing boundaries, degenerate demands) so you catch modelling mistakes instead of chasing a bad number afterwards.

validationmodel checkgraph validationpreflight

undoredohistoryjump to stateCtrl+Ztime travel

Undo / redo with jump-to-state history

Step backward and forward through every edit, or open the History panel and jump straight to any earlier state of the network — so an experiment on the model is never a one-way door.

Model Builder → Toolbar → History

Keyboard-shortcut overlay

Press “?” anywhere on the canvas for a categorized cheat-sheet of every keyboard shortcut, so the fast paths are always one keystroke away.

keyboard shortcutshotkeyscheat sheetproductivityhelp overlay

Model Builder → press “?”

Canvas minimap

A live minimap in the corner of the canvas shows the whole network at a glance and lets you jump around a large model without losing your place.

minimapcanvasnavigationoverviewlarge network

Model Builder → canvas

Spawn Defaults presets

Set the default properties new nodes and pipes are created with — diameter, material, roughness, and more — so a whole model is drawn in your standard sizes without re-typing them on every element.

spawn defaultspresetsdefaultsnew elementproductivity

Model Builder → Tools menu → Spawn Defaults…

Custom flowsheet labels

Choose which fields show on each node and pipe on the canvas — tag, size, flow, pressure — so a schematic reads like your own flowsheet convention rather than a fixed default.

flowsheet labelscanvas labelsannotationstagreadoutcustomization

Model Builder → Tools menu → Custom Flowsheet Labels…

Autosave & snapshot restore

The builder autosaves the whole project — network, fluid, units, transient setup, and solver settings — to your browser every few seconds and offers to restore it on reload, so a refresh or crash never loses your work.

autosavesnapshotrestorerecoverypersistencelocalStorage

Model Builder

Global unit system & custom result units

Switch the whole model between SI and US units, or set a custom unit per result category (velocity in ft/s, pressure in bar, and so on) — the display everywhere follows your choice.

unitsSIUS customaryunit systemcustom unitsconversion

Model Builder → Header → Project Settings → Unit System

Named run history — save, recall & compare

Save a solve as a named run, recall it later, and compare two runs side by side to see exactly what changed between design iterations — autosaved automatically so a browser refresh never loses a solve.

run historysaverecallcompareautosaveversion

Model Builder → Run history

Relatedproject workspace

Prototype-area warning banner

A visible banner flags builder areas that are still experimental or not yet final, so you know upfront which results to treat as provisional rather than discovering the caveat after the fact.

prototypewarning bannerexperimentalhonestydisclosure

Model Builder

Per-link thermal / insulation config

Mark any pipe buried or above-ground and set its ambient temperature, burial depth, soil, and insulation directly on the link — the input that feeds the marching engine's ambient heat-transfer and condensation results.

thermal configinsulationburied pipeambient temperatureper-link

Model Builder → pipe → Thermal/Insulation tab

Relatedambient heat transfer

Condensation & two-phase per-link results

Read inlet-to-outlet steam quality, heat loss, and temperature alongside flow pattern, void fraction, mixture density, and holdup for each pipe — the detail behind a condensing or two-phase line, not just a pass/fail.

two-phase resultscondensationflow patternvoid fractionholdupsteam quality

Model Builder → pipe results

steam trapcondensateseries topologynode resultspressure drop

Steam-trap node results

A Steam Trap node reports its status, condensate flow, outlet quality, and pressure drop, modelled in the correct series topology rather than incorrectly splitting flow in parallel.

Model Builder → Steam Trap node → results

Relatedsteam-trap assist

Gas per-link result readouts

Every gas pipe reports Mach number, density, mass flow, a CHOKED badge when it hits sonic velocity, an erosional-velocity status against API 14E, and the Weymouth-equivalent standard flow — the full compressible picture per link.

gas resultsMach numberchoked flowerosional velocityWeymouthAPI 14E

Model Builder → pipe results (gas mode)

Relatedcompressible gas mode

Fluid property / correlation viewer

Drill into any solved node or pipe's fluid properties to see the actual correlation used from the fluid database plotted as a temperature-varying chart, instead of taking a single property value on faith.

fluid propertiescorrelationT-varyingFDBproperty viewer

Model Builder → node/pipe results → property detail

Relatedfluid properties calculator

Builder Editing & Tools

Canvas-level editing conveniences — selection, alignment, snapping, and view controls — that make arranging a network model fast.

Dynamic handle reconnection

Drag a node anywhere on the canvas and its connected pipes follow automatically, attaching at a single centre handle so links stay connected as you rearrange the model without manual re-drawing.

handle reconnectioncanvasdragauto-routingpipe endpointsUX

Model Builder → canvas

FCV Cv-curve visualization

See a flow-control valve's Cv curve plotted with its current operating point marked, so you can judge at a glance whether the valve is sized and positioned sensibly rather than reading a bare Cv number.

FCVCv curvecontrol valveoperating pointvisualization

Model Builder → Control Valve node → results

Relatedcontrol valve Cv calculator

Interactive pump-curve editor

Edit a pump's Q-H, efficiency, and NPSH-required curves directly in a FluidFlow-style graphical editor, with Flow/Head unit dropdowns and an explicit discharge-side picker, instead of typing coefficient tables blind.

pump curveQ-H curveNPSHefficiency curvecurve editorFluidFlow

Model Builder → Pump node → Curve editor

Relatedpump catalog library

Configurable canvas tooltips

Hover any node or pipe for a tooltip you control — pick which fields show per model-type, and adjust font and box width — so the canvas stays readable whether you want a quick glance or a detailed readout.

tooltiphovercanvasconfigurableUXreadout

Model Builder → canvas → tooltip settings

Multi-select & bulk edit

Rectangle- or lasso-select a whole region of the canvas and edit a shared property across every same-type element at once — change twenty pipes' roughness in one action instead of twenty clicks.

multi-selectlasso selectbulk editrectangle selectbatch

Model Builder → canvas (drag to select)

Right-click align & distribute

Right-click a multi-selection for a PowerPoint-style align/distribute menu — line up nodes horizontally or vertically and space them evenly, so a hand-built network looks like a drafted drawing.

aligndistributelayoutright-click menucanvas tidy

Model Builder → canvas (right-click on selection)

Copy / paste / duplicate

Ctrl+C / Ctrl+V / Ctrl+D a selection to reuse a sub-network — a tank-and-pump skid, a metering run — instead of rebuilding the same pattern by hand every time it recurs.

copypasteduplicatekeyboard shortcutreuse

Model Builder → canvas (Ctrl+C/V/D)

Snap-to-grid & isometric view

Snap nodes to a grid while placing them, and toggle between a flat 2D layout and an isometric view of the same network — useful when a drawing needs to read like a piping isometric rather than a schematic.

snap to gridisometric2Dview togglelayout

Model Builder → canvas → view toggle

Sticky placement tool

Keep an add-node tool selected after each drop so you can place a whole row of identical elements — sprinkler heads, junctions — back to back without re-picking the tool every time.

sticky toolplacementrapid placementtoolbarUX

annotationslabelsdisplay pillscanvas toggledeclutterview options

Canvas annotation toggles

Toggle what the canvas shows with the Toolbar display pills — node names, pipe names, quick results, and hover tooltips — so you can declutter for a screenshot or turn every id and value back on while editing.

Model Builder → Toolbar → display pills (node names / pipe names / quick results / tooltips)

Model image capture (PNG / SVG)

Export a clean PNG or SVG image of the whole network from the File menu — a fully-visible screenshot of the model for a report or drawing — and fit the canvas to the model’s bounding box with the fit-to-view control.

capturescreenshotexport imagePNGSVGfit to view

Model Builder → Header → File → Capture Model Image (PNG / SVG)

Solver & Fluid Modes

One network, many physics engines: steady liquid, compressible gas, slurry, flare, rigorous two-phase, extended-period, and non-Newtonian.

Steady-state network solver (GGA)

Solves incompressible pipe networks with the Global Gradient Algorithm in dense and sparse forms, verified byte-identical to EPANET to 1e-10 on benchmark networks. The credible backbone every other mode builds on.

GGAglobal gradient algorithmEPANET paritysteady statenetwork solversparse solver

Darcy-WeisbachColebrook-WhiteHazen-WilliamsSwamee-Jainfriction factorhead loss

Friction models (DW · Colebrook · HW)

Choose Darcy–Weisbach (Swamee–Jain), the exact iterative Colebrook–White, or Hazen–Williams for head loss — with fire paths promoted to Hazen–Williams per NFPA-13. Friction is the backbone, so it is kept correct across every mode.

Model Builder → Project Settings → Friction model

Compressible gas mode

Solves gas networks with Peng–Robinson / GERG-2008 equations of state, choked-flow detection, and Weymouth / Panhandle correlations, including Joule–Thomson temperature change on pressure let-down.

compressible gasPeng-RobinsonGERG-2008choked flowWeymouthPanhandleJoule-Thomson

slurrysettling slurryWilsondeposition velocityAFT SSLminingdredging

Settling-slurry mode

Adds Wilson deposition-velocity physics as a minor-loss on the carrier friction, with per-link mixture SG, slurry static head, and a deposition-margin gate that blocks the datasheet below the deposition velocity. Answers the AFT SSL question.

Model Builder → Project Settings → Slurry mode

Flare-header rating (API 521)

Rates a flare / relief header network by fixing the tip pressure and injecting each relief source as flow, then checks built-up backpressure against every device MABP across multiple contingency scenarios (global fire, power failure, single-valve). The FLARENET answer.

flare headerAPI 521FLARENETbuilt-up backpressureMABPreliefcontingency scenarios

Model Builder → Project Settings → Flare header mode

Marching multi-fluid two-phase engine

A rigorous coupled thermo engine that marches property-by-property along each pipe to resolve flow pattern, liquid holdup, in-situ density, vapor quality, and phase change for multi-fluid and two-phase lines — beyond a wrapped correlation.

two-phasemulti-fluidmarchingflow patternholdupvapor qualitythermo coupling

heat transferambientinsulationburied pipeheat lossthermal

Ambient heat transfer in pipes

The marching kernel applies per-segment heat loss or gain to ambient (buried or above-ground) so a hot or cold line cools or warms realistically along its length, changing outlet temperature and quality. Reuses the Heat Transfer panel with no extra setup.

Model Builder → Heat Transfer panel

Extended-period simulation (EPS)

Drives demands and tank levels over time so you can watch a system fill, draw down, and rebalance across a daily cycle rather than at a single snapshot. Rules-free time integration in the spirit of EPANET EPS / AFT XTS.

EPSextended perioddemand patterntank integrationtransient demandAFT XTS

Model Builder → Project Settings → EPS

Non-Newtonian rheology

Handles power-law, Bingham-plastic, and Herschel–Bulkley fluids with exact power-law wall shear, so slurries, sludges, muds, and pulp get a defensible pressure drop instead of a water approximation.

non-Newtonianpower-lawBinghamHerschel-BulkleyrheologyRabinowitsch-Mooney

Model Builder / calculators

Marching per-pipe hydraulics reporting

On the marching engine, every pipe reports its own Reynolds number, friction factor, and head loss alongside flow pattern, liquid holdup, in-situ density, exit Mach, and ambient heat — the per-pipe detail the GGA path shows, now on the property-marching engine too.

marchingper-pipeReynoldsfriction factorhead lossholdupreporting

Model Builder → select a pipe → Results

phase detectorphase classificationvapor liquidsupercriticaltwo-phaseEOS

Automatic fluid-phase detector

Classifies every boundary node and result into one of six physical phases (and four practical buckets — liquid/vapor/two-phase/supercritical) automatically from the solved pressure and temperature, so you don't have to guess which physics apply before reading a result.

Model Builder → Run → node results

teebendminor lossSAE ARP1168ESDU 83037MillerK factorfitting

Tee & bend minor-loss correlations (SAE ARP1168 / ESDU 83037 / Miller)

Computes tee and bend K-factors from closed-form SAE ARP1168-1 (tees) and ESDU 83037 (bends) correlations, plus the Miller (Internal Flow Systems) method, instead of a single flat table value — so branch and elbow losses track geometry and flow split correctly in the network solve.

Model Builder → pipe properties → fittings

Correlation-driven fluid property engine (FDB)

Feeds the solver live density, viscosity, vapor pressure, and thermal properties from a 1,000+ fluid correlation database instead of fixed constants, so properties respond correctly to the solved pressure and temperature at every point along a run.

fluid databaseFDBcorrelationproperty lookupthermophysical properties

Model Builder → Database → Fluid Editor

AGA-8 transmission-grade Z-factor & erosional velocity

Adds AGA-8 detailed-characterization compressibility as a custody-transfer-grade alternative to GERG-2008/Peng–Robinson, and screens every gas line for erosional velocity per API RP 14E so an oversized-velocity line is flagged instead of silently passing.

AGA-8Z-factorgas transmissionerosional velocityAPI RP 14Ecompressibility

compressorgas networkpolytropicfixed ratiofixed dischargeGPSA

Relatedcompressible gas mode

Gas compressor element (fixed-discharge / fixed-ratio / polytropic)

Places a compressor inline in a gas network with fixed-discharge-pressure, fixed-ratio, or polytropic-efficiency operating modes, coupling the compression work into the downstream pressure and temperature the rest of the network sees.

Model Builder → node palette → Compressor

Relatedprocess blower rating calculator

Two-phase closure model library (HEM / Lockhart-Martinelli / Beggs-Brill / Friedel)

Switches between Homogeneous-Equilibrium, Lockhart-Martinelli, and Beggs-Brill pressure-drop correlations with a Friedel (1979) two-phase friction multiplier as the default closure, through a pluggable seam so a different multiplier can be swapped in without touching the marching engine.

two-phaseHEMLockhart-MartinelliBeggs-BrillFriedelfriction multiplierpressure drop

flow patternBarneaholdupslug flowstratified flowannular flowdrift flux

Flow-pattern map & in-situ holdup (Barnea)

Classifies the two-phase flow regime along a pipe — stratified, slug, annular, bubble — with the Barnea (1987) unified map, then computes liquid holdup with a regime-specific model (level / drift-flux / film) instead of assuming a single homogeneous mixture.

separatorsteam trapphase routingmarching enginevapor liquid split

Relatedtwo-phase closure model library

Marching separator / steam-trap phase routing

Solves a separator or steam-trap node as its own square nodal system in the marching engine so vapor and liquid phases split and route to the correct downstream pipe instead of leaving the network with one blended stream.

IEC 60534control valvemarching engineTCVPBVGPVFCVPRVPSV

Marching-engine valves (IEC 60534, 6 types)

Sizes and resolves all six valve types — TCV, PBV, GPV, FCV, plus PRV and PSV pressure regulators — with IEC 60534 flow coefficients directly inside the marching thermo engine, so valve pressure drop and any resulting flashing stay coupled to the rest of the pipe's property march.

choked flowsonic velocitymarching enginecompressiblesafety guard

Marching sonic-choke guard

Detects when a line in the marching engine reaches sonic (choked) velocity and caps the solved flow at the physical limit instead of returning a solved flow that violates compressible-flow physics.

phase changevaporizecondenseflashingcondensationmarching engine

Marching phase-change detection (vaporize / condense)

Watches enthalpy and pressure as the marching engine steps along a pipe and detects exactly where a subcooled liquid starts to flash or a superheated vapor starts to condense, switching the local physics at that point instead of assuming one phase for the whole line.

pumpmarching engineNPSHvariable speedF07

Marching-engine pumps (F07)

Runs a pump's real head-vs-flow curve, variable-speed ratio, and NPSH margin check inside the marching thermo engine (not just the steady GGA path), so a pumped two-phase or multi-fluid line gets a correct operating point end to end.

Model Builder → Multi-Fluid examples → Pump (marching)

Relatedpumps & compressors

Ideal-mixing gas blend for flare headers

Blends multiple relief-source gas compositions into one ideal-mixing pseudo-species (Kay's-rule pseudo-criticals, exact mixture molecular weight) so a flare header carrying more than one gas gets a genuine blended property set instead of rating on a single named gas.

gas blendideal mixingKay's ruleflare headercompositionpseudo-critical

Model Builder → Project Settings → Flare header mode

Relatedflare-header rating

EPS control & rule engine (EPANET CONTROLS/RULES)

Runs EPANET-style [CONTROLS] and [RULES] logic during an extended-period simulation so pumps and valves genuinely switch on level, time, or pressure triggers as the simulation steps, not just a fixed demand/tank pattern.

EPSEPANETCONTROLSRULESrule-based controlpump schedulevalve schedule

Model Builder → Project Settings → EPS → Rules

Relatedextended-period simulation (EPS)

Six-type EPANET valve engine (PRV/PSV/FCV/PBV/TCV/GPV)

Models all six EPANET valve types — pressure-reducing, pressure-sustaining, flow-control, pressure-breaker, throttle-control, and general-purpose — with the same active/inactive big-coefficient pinning method EPANET uses, so valve state switches match the reference tool instead of oscillating or mis-converging.

PRVPSVFCVPBVTCVGPVEPANETvalve enginebig coefficient

Model Builder → node palette → Control/Isolation valves

Warm-start solving

Reuses the previous converged solution as the initial guess for the next solve, so scenario sweeps, EPS time steps, and small parameter tweaks converge in fewer iterations than starting cold every time.

warm startinitial guessconvergenceperformanceNewton iteration

engine routerauto-routingGGAmarching enginephase-change safety

Automatic solver-engine router

Picks the right physics engine for a network automatically — steady GGA, compressible gas, or the marching multi-fluid engine — including a safety rule that routes a line to marching whenever phase change is possible, so you don't have to know which engine a model needs before running it.

heat exchangerfix dutyfix delta Tnetwork nodeenergy balance

In-network heat-exchanger sizing modes (Fix Duty / Fix ΔT)

Lets an inline Heat Exchanger node be solved two ways — pin a fixed duty or a fixed outlet ΔT — so the surrounding network solve gets a determinate energy balance across the exchanger without leaving the network under-specified.

Model Builder → node palette → Heat Exchanger

Relatedheat exchanger calculator

Mixed-SG slurry static head (per-node, F06 v3)

Approximates the correct static head in a slurry network where different legs carry different mixture specific gravity, using a per-node BFS-derived SG rather than one network-wide value, and blocks (rather than silently mis-solves) sharp-SG legs it can't yet resolve exactly.

slurrystatic headmixture SGspecific gravitycorrect-or-loud

Model Builder → Project Settings → Slurry mode

Relatedsettling-slurry mode

Transient & Surge Analysis

Water-hammer and surge in the time domain — wave propagation, column separation, gas transients, and protection sizing.

Water-hammer (Method of Characteristics)

Simulates pressure surge from valve closures and pump trips with an MOC engine (Courant=1 exact) that captures Joukowsky peaks, wave reflection, and network junction coupling. Honors instantaneous, linear, exponential, and two-stage closure laws.

water hammerMOCmethod of characteristicsJoukowskysurgeAFT Impulsetransient

Model Builder → Transient panel

Column separation (DGCM cavitation)

Detects and models vapor-cavity formation and collapse with a Discrete Gas Cavity Model — pinning the head at vapor pressure and tracking the cavity through formation and collapse rejoin, including at the valve boundary where column separation most often occurs. Validated against Aalborg / Bergant surge experiments to within a few percent of the measured peak, and stays conservative through the first cavity cycle.

column separationDGCMcavitationvapor cavityvalve boundaryvapor pressuretransientWylie StreeterBergant

Model Builder → Transient panel (enable column separation)

Gas-line transient

A dedicated single-line isothermal gas-transient engine (MOC, Courant=1) validated against exact closed-form solutions with friction, for blowdown and valve-transient pressure waves in gas piping. A low-Mach envelope keeps it correct-or-loud, and wet-steam / condensation is refused rather than mis-modelled.

gas transientisothermalblowdownline packAPI gascompressible transientMach envelope

Model Builder → select a pipe → Gas Transient tab

Relatednetworked gas transient

Networked gas transient

The multi-line successor to the single gas line: coupled gas transients across a network with junction mass and pressure continuity, for pressure waves that propagate through a header rather than a single pipe. Carries the same T-register honesty as the single line — a shared common-Δt mesh note (T25), a low-Mach envelope (T19), and a wet-steam / condensation refuse (T20).

gas transientnetworkjunction continuitymulti-lineheader transientcompressibleT25Mach envelope

API: POST /gas-network-transient

Relatedsingle gas-line transient

Transient forces → CAESAR II export

Export transient hydraulic forces to a CAESAR II load set — or as a forces-only CSV, a JSON forces file, Excel, or PDF — handing surge loads straight to a pipe-stress model.

CAESAR IIexporttransient forcespipe stressinteroperabilityload setJSONCSV

Model Builder → Transient panel → Export

Relatedinteroperability

Surge-protection sizing

Sizes air chambers, surge tanks, flywheels, and surge-relief valves to keep transient pressures within pipe ratings, with input validation that refuses non-physical requests instead of returning negative volumes.

surge protectionair chambersurge tankflywheelsurge relief valvesizing

Model Builder → Surge Protection

Pump-trip (4-quadrant)

Models a pump trip using four-quadrant Suter curves so reverse-flow and reverse-rotation behavior after power failure is captured, driving realistic downstream surge.

pump trip4-quadrantSuter curvepower failurereverse flowtransient

Model Builder → Transient → Pump trip

Water-hammer quick calculator

A standalone calculator for the surge peak from a valve closure via Joukowsky / Michaud, with a P-vs-t waveform, cavitation check, and comparison against pipe pressure rating — no full model required.

water hammerJoukowskyMichaudcalculatorvalve closure

/calculators/water-hammer

Wave-speed calculator

A built-in Korteweg wave-speed (celerity) helper in the Transient panel computes the pressure-wave speed from pipe material, wall thickness, and fluid, so the surge timing that drives every transient result starts from a defensible number.

wave speedcelerityKortewegtransientwater hammersonic

Model Builder → Transient panel → Wave Speed

One-click quick transient screens

Beyond the single-pipe pump trip, the Transient panel offers one-click Quick screens for a fast valve closure, a pump startup (with a startup-curve run-up law), and a pipe burst — a first read on surge risk without building a full scenario.

quick analysisvalve closurepump startupstartup curvepipe bursttransient screen

Model Builder → Transient panel → Scenarios → Quick Analysis

Relatedquick pump-trip transient

Async transient job queue

Long transient analyses can be submitted to a background job queue that returns a job id to poll (and cancel), so a big MOC run does not tie up the request. Available over the API today.

asyncjob queueCelerybackgroundtransientpolling

API: POST /jobs/transient

Valve closure patterns (closure-law selector)

Choose how a valve closes during a transient run — instantaneous, linear ramp, exponential decay, or a two-stage fast/slow profile — because the closure law materially changes the surge peak a fast finish-stage closure sees versus a naive linear assumption.

valve closureclosure patterninstantaneouslinearexponentialtwo-stagetransient

Model Builder → Transient panel → Scenarios (valve closure pattern)

Relatedwater-hammer MOC engine

Unsteady-friction models (Vitkovsky / Brunone / Vardy-Brown)

Go beyond quasi-steady pipe friction during a transient with an instantaneous-acceleration (Vitkovsky/Brunone) term or a Vardy-Brown convolution-based weighting-function model, tightening the predicted damping and decay of a surge wave train.

unsteady frictionVitkovskyBrunoneVardy-Brownconvolutiondampingtransient friction

Model Builder → Transient panel → Enhanced (Friction model)

Quick pump-trip transient (single pipe)

Run a one-click single-pipe pump-trip surge screen — power failure, flow deceleration, and downsurge — without building a full network model, for a fast first read on trip risk.

pump tripquick analysispower failuredownsurgesingle pipetransient

Model Builder → Transient panel → Scenarios → Quick Pump Trip

Related4-quadrant pump-trip network BC

Suter 4-quadrant pump-curve library

Pick from a typed, sourced library of AFT-style four-quadrant (Suter) pump curves for pump-trip transients — or import your own via CSV — instead of relying on an unphysical toy curve that can fail to converge in the reverse-flow quadrants.

Suter curve4-quadrantpump curve librarypump tripCSV importAFT

Model Builder → Pump node → Advanced → Pump-Trip Data → Four-Quadrant Curve

Check-valve flow-reversal latch

During a pump-trip or flow-reversal transient, a check valve latches shut the instant flow tries to reverse — with a hardened Newton solve that keeps the surge calculation converging through the event — instead of being treated as always-open.

check valveflow reversallatchpump tripNewton solvetransientnon-return valve

Model Builder → Transient panel (automatic on pump-trip / reversal scenarios)

Relatedcheck-valve slam test

DGCM junction-node column separation

Models vapor-cavity formation at an interior multi-pipe junction — not just at valves — as a first-class node cavity, cross-checked against an equivalent split-pipe model to machine precision (~1e-13 m).

DGCMcolumn separationjunction cavitymulti-pipecavitationnetwork transient

Model Builder → Transient panel (enable column separation, multi-pipe network)

Network water-hammer solver (multi-pipe MOC)

Runs the Method-of-Characteristics wave solve across an entire piping network at once — not just one pipe — coupling junctions, branches, and every surge-protection device into a single time-domain transient.

network MOCmulti-pipewater hammerjunction couplingtransientwave propagation

Model Builder → Transient panel

Relatedsingle-pipe water-hammer MOC

Air-chamber surge protection (network device)

Place a gas-cushioned air chamber as a boundary condition anywhere in a transient network model, damping surge peaks and column-separation risk at the point you tee it in — e.g. at a pump discharge on a long rising main.

air chambersurge protectiongas cushionnetwork nodetransientrising main

Model Builder → add node → Air Chamber

Relatedsurge-protection sizing

Surge tank (open standpipe device)

Model an open free-surface surge tank as a network node — a low-pressure, low-maintenance surge-relief option for systems where an elevated open standpipe is practical.

surge tankstandpipefree surfacesurge protectionnetwork nodetransient

Model Builder → add node → Surge Tank

Feed (one-way) tank with check valve

Model a one-way feed tank — a standpipe gated by a check valve that only admits makeup water when line pressure drops — a compact alternative to a full surge tank at a vulnerable low point.

feed tankone-way surge tankcheck valvestandpipesurge protectiontransient

Model Builder → add node → Feed Tank

Air/vacuum valve (AVV)

Model an air/vacuum valve that admits air the instant line pressure drops below atmospheric, preventing pipe collapse and vapor-cavity growth at a high point, then expels it on refill.

air vacuum valveAVVair admissionvacuum breakersurge protectiontransient

Model Builder → add node → Air/Vacuum Valve

Transient (surge) relief valve

Model a pressure-actuated relief device that opens during a transient once the local pressure crosses its set point, discharging flow to cap the surge peak instead of letting it ring through the network unchecked.

relief valvesurge reliefpressure relieftransientoverpressure protectionnetwork node

Model Builder → add node → Surge Relief Valve

Transient pipe support & thrust forces

Computes the directional support and thrust forces a transient wave imposes on pipe runs and elbows — anchored to the Joukowsky pressure rise — so a surge event can be checked against pipe-support design, not just peak pressure.

thrust forcesupport forceJoukowskypipe stressdirectional forcetransient

Model Builder → Transient panel → Results (Force summary)

RelatedCAESAR II force export

Pressure-envelope summary, profile & play/scrub

Reads the real MOC spatial max/min pressure along every pipe as a per-pipe summary table (peak surge, lowest pressure, and where each occurs, with a vacuum-risk flag) and a profile chart — then a play/scrub transport animates the instantaneous pressure sweeping through time inside that envelope. Driven by the actual solved results, not a demo waveform.

pressure envelopesurge profileplay scrub animationmax min pressurevacuum risktransientwave propagation

Model Builder → Transient panel → Results

Common-Δt mesh selection

Automatically picks one shared MOC time step across pipes of different, non-commensurate lengths in a network, cutting wave-timing error from a multi-percent mismatch down to a fraction of a percent instead of forcing pipe lengths onto a convenient grid.

meshtime stepCourantnon-commensuratenetwork MOCnumerical accuracy

Model Builder → Transient panel (automatic, multi-pipe networks)

Per-pipe transient friction from roughness

Derives each pipe's transient friction factor from its own roughness and the steady-state solve (an 'Auto' default) instead of applying one fixed friction value network-wide, so surge damping reflects the actual pipe, not a guess.

friction factorroughnessauto frictionper-pipetransientsurge damping

Model Builder → Transient panel → Config (Friction Factor → Auto)

Auto-Sizing & Optimization

Let the tool pick pipe sizes and pump duty for you — least-cost sizing, goal-seek, and a provenance-stamped pump catalog.

Network auto-sizing (least-cost)

Automatically selects pipe diameters to meet velocity and pressure targets at least cost — over per-pipe size groups and weighted multi-case design scenarios (v2) — certifying feasibility with a real cold solve so it never hands back a size that fails to converge. The AFT ANS answer.

auto sizingleast costoptimizationpipe sizingAFT ANS1-optsize groupsmulti-case

Model Builder → Auto-Size

Goal-seek

Solve backwards: fix a target (a pressure, a flow, a velocity) and let the tool find the input that hits it. The AFT GSC answer.

goal seekinverse solvetargetAFT GSCdesign point

Model Builder → Goal-Seek

Pump catalog library

Search a provenance-stamped pump-curve library, BEP-ranked against your duty point, and apply a real curve and speed to a node in one click — with a clear curated vs user-supplied trust tier plus a certified tier (certificate ref + revision) for vendor-verified curves. Maintain your organization's own pumps with full CRUD and bulk CSV import. The PIPE-FLO PUMP-FLO answer.

pump catalogpump curve libraryBEPprovenancecertifiedCSV importPUMP-FLOPIPE-FLO

Model Builder → Pump → Select from library

Cost analysis

Estimate capital and operating cost of a network so sizing decisions can be weighed on money, not just hydraulics.

costcapexopexlife cycle costeconomics

/cost

User pipe cost tables

Create, edit, and manage your organization’s own pipe cost tables (per material, size, and currency) and point auto-sizing at them, so a least-cost result reflects your real prices instead of a built-in default.

cost tablepipe costauto sizingleast costuser dataF01

Model Builder → Auto-Size → Manage cost tables…

Relatednetwork auto-sizing

Analysis & Workspace Tools

Study a network beyond a single solve — scenario trees, sensitivity, control loops, standards checks — and save, share, and version your work.

Scenario trees & tornado sensitivity

Branch a base model into named scenarios (parameter changes), batch-run them, and rank which inputs move the answer most with a tornado sensitivity chart. Compare scenarios side by side without rebuilding the network.

scenariosensitivitytornado chartbatch runparametric studywhat-ifvariationsAFT scenario

Model Builder → Tools → Scenarios

PID control-loop simulation

Add PID control loops to a network — set point, mode, tuning, and diagnostics — and simulate how the controlled variable responds. A full loop-management subsystem, not just a fixed valve position.

control loopPIDcontrollertuningsetpointprocess controlinstrumentation

Model Builder → Tools → Control loops

Relatedcontrol valves

Water-quality simulation

Track a reactive constituent (e.g. chlorine decay) through the network over an extended-period run, on top of the tank/demand time simulation. Reaction-kinetics models, not just hydraulics.

water qualitychlorine decayreactionconstituent transportEPANET water qualityage

Model Builder → Water quality

Relatedextended-period simulation

Design alerts & standards limit checks

Check solved velocities, pressures, and other quantities against configurable, standards-based limits and get flagged where a design breaches them — a design-review layer distinct from the solver honesty notes.

design alertslimit checkstandardsvelocity limitpressure limitdesign reviewcompliance

Model Builder → Design Alerts

check valveslamwater hammernon-return valvereverse flowtransient risk

Check-valve slam test

Screen a check valve for slam / water-hammer risk from its placement and the reverse-flow it would see — a targeted transient safety check on top of the node type.

Model Builder → check-valve slam test

Relatedtransient & surge

In-builder equipment sizing tabs

Size equipment straight from a solved node: free-water 3-phase flash check, compressor/pump-trip settle-out pressure, flashing / two-phase relief (API 520 Omega), bursting disk, gas relief, orifice, and heat-exchanger — the "size this device from the solve" workflow.

sizingsettle-outfree water flashflashing reliefbursting diskorificeheat exchangerAPI 520

Model Builder → element results → sizing tab

Relatedrelief & safety calculators

Decision-support verdicts (Element-Assist)

Selected builder elements and many calculators return a pass / warn / fail verdict with the reason and a fix — pump NPSH & BEP window, control-valve choke, sprinkler 7-psi, check-valve slam, HX pinch, orifice cavitation, per-pipe pressure rating, and more. Numbers plus an engineering read on them.

assistverdictpass faildecision supportdiagnosticsNPSHBEPadvisorycalculation assistant

Model Builder → element results

projectsavesharerun historyworkspacecollaborationversions

Project workspace — save, share & run history

Save named network projects, keep a per-project run history, and share a model with teammates. A persistence and collaboration layer over the builder, beyond the read-only example library.

/projects/hydraulic

Relatedthe model builder

Solver Diagnostics panel

With nothing selected, the right panel becomes a Solver Diagnostics dashboard — solver status and matrix-health metrics, warnings, choked-flow flags, and a convergence-history chart of residual vs iteration — so "Converged" is something you can inspect, not just a claim.

solver diagnosticsconvergenceresidualmatrix healthiterationtransparency

Model Builder → deselect all → Solver Diagnostics

parameter explorersweepwhat-ifsensitivitysliderlive

Parameter Explorer (live sweep)

Pin any input — a diameter, a demand, a pump speed — and a floating Parameter Explorer lets you sweep it with a slider and watch the solved answer move in real time, for quick what-if intuition without a full scenario run.

Model Builder → pin a parameter → Parameter Explorer

Relatedscenario trees & sensitivity

Head-loss breakdown

Select a pump after a solve and see where its head is going — a per-pipe head-loss breakdown across the connected loop, sorted by contribution, so the biggest losses in a system are obvious rather than buried.

head lossbreakdownattributionpumploss contributiondiagnostics

Model Builder → select a Pump → Head Loss Breakdown

Reviewer continuity-residual calc sheet

Generate a node-by-node continuity-residual review sheet for a solved model — a reviewer-facing check that every junction actually balances, for a second engineer to sign off on before the model is trusted.

reviewercontinuity residualcalc sheetmass balancepeer reviewaudit

Model Builder → Run → Reviewer calc sheet

Relatedcalculation sheets

Four-gate convergence transparency

See the solver's own internal convergence gates — the checks it runs before declaring a solve converged — surfaced in the builder UI, so "Converged" means something you can inspect rather than a black-box claim.

convergencetransparencysolver gateshonestydiagnostics

Model Builder → Run → Convergence detail

compressorsurge marginoperating pointverdictElement-Assist

Compressor operating-point verdict

A compressor node gets an inline pass/fail verdict on its operating point plus surge-margin inputs, catching a compressor running too close to its surge line directly in the builder results.

Model Builder → Compressor node → results

Relateddecision-support verdicts

Steam-trap flooding/stall assist

Detects flooding and stall conditions on a steam-trap node and reports them with a model-honesty note, so a trap that's misbehaving in the model is flagged rather than silently passing condensate that shouldn't get through.

steam trapfloodingstallassistmodel honestyElement-Assist

Model Builder → Steam Trap node → results

Relatedsteam-trap node results

Surge-device adequacy verdict

After a network transient run, judges whether the surge-protection devices in the model — air chambers, surge tanks, relief valves — are actually adequately sized for the surge they just saw, not just present.

surge deviceadequacyverdicttransientsurge protectionElement-Assist

Model Builder → Transient panel → surge-device results

Relatedsurge-protection sizing

Fire Protection

NFPA-code fire hydraulics — sprinkler systems, water-spray / deluge, foam, and fire-pump sizing.

NFPA-13 sprinkler hydraulics

Runs the density/area and most-remote-area method with Hazen–Williams head loss to size sprinkler systems and hand the required flow and pressure to the fire pump.

NFPA 13sprinklerdensity areamost remote areaHazen-Williamsfire

/calculators/sprinkler-hydraulic

NFPA-15 water-spray / deluge

Designs open-nozzle deluge systems where every head flows simultaneously (Q = K·√P), then checks the delivered density over a vessel or transformer surface for cooling.

NFPA 15delugewater sprayopen nozzlevessel coolingfire

/calculators/water-spray-deluge

NFPA-16 foam-water

Extends deluge design with a foam-solution split and proportioner pressure drop for foam-water spray systems.

NFPA 16foamproportionerfoam-waterfire

/calculators/water-spray-deluge

Fire-pump sizing (NFPA-20)

Checks a fire pump against the NFPA-20 curve envelope (shutoff ≤ 140%, ≥ 65% head at 150% flow), suction pressure, jockey-pump sizing, and driver power with diesel deration.

NFPA 20fire pumpjockey pumppump envelopediesel derationfire

/calculators/fire-pump-sizing

Sprinkler FluidFlow-parity parameter tree

Every sprinkler node exposes the full Element Properties parameter set — K-factor, orifice size, thermal response, coverage area, temperature rating — matching the parameter tree engineers already know from FluidFlow, so a model transfers without relearning field names.

sprinklerFluidFlowparameter treeK-factorNFPA 13element properties

Model Builder → Sprinkler node → Properties

RelatedNFPA-13 sprinkler hydraulics

NFPA-13 §28.4 form templates

Generates the NFPA-13 §28.4 hydraulic calculation package straight from a solved sprinkler model — the Summary sheet, the node-by-node Worksheet, and the graphical N^1.85-linearized paper — in the layout an AHJ expects to review.

NFPA 13§28.4hydraulic calculation formsummary sheetworksheetN^1.85 graphAHJ

Model Builder → Fire calc export

Relatedsupply-vs-demand graph

One-click "Fire calc" export

Maps a solved sprinkler network straight onto the NFPA-13 §28.4 form set with one click, so the compliance paperwork always reflects the exact model that was solved instead of a hand re-keyed copy.

fire calcNFPA 13§28.4exportcompliancesprinkler

Model Builder → Run → Fire calc

RelatedNFPA-13 §28.4 form templates

NFPA sprinkler layout generator

Turns density, coverage area per sprinkler, and spacing (S × B) into an auto-generated, solvable sprinkler grid — with a live-recomputed summary in the generator dialog before you confirm — instead of placing every head and branch pipe by hand.

sprinkler layoutlayout generatordensity areaspacinggridNFPA 13auto-generate

Model Builder → Generate sprinkler layout

RelatedNFPA-13 sprinkler hydraulics

Curated manufacturer sprinkler catalog

Pick a real sprinkler head from a provenance-typed manufacturer catalog — K-factor, temperature rating, response type — and apply it to a node in one click instead of transcribing a K-factor off a cut sheet.

sprinkler catalogmanufacturerK-factorprovenancepickerNFPA 13

Model Builder → Sprinkler node → Pick sprinkler model

Relatedpump catalog library

Per-user sprinkler-model library

Save your own sprinkler models with a provenance dossier alongside the curated manufacturer set, so a project can standardize on a specific vendor's head across every network you build.

sprinkler libraryuser libraryprovenanceCRUDsprinkler modelNFPA 13

Model Builder → Sprinkler node → My sprinkler models

Fire Design Basis panel

Captures the NFPA-13 design-of-record envelope in one place — occupancy hazard classification, the dual density-and-area design points, hose-stream allowance, and the 2-point water-supply test — so the basis of a sprinkler design is documented with the model, not lost in a separate memo.

fire design basisoccupancy hazarddensity areahose streamwater supply testNFPA 13

Model Builder → Project Settings → Fire Design Basis

Relatedsupply-vs-demand graph

Supply-vs-demand graph (§28.4.6)

Plots the water-supply curve against the sprinkler system's hydraulic demand on N^1.85-linearized axes per NFPA-13 §28.4.6, so the margin between what's available and what's required reads as a straight line at a glance.

supply demand graphN^1.85§28.4.6water supply curveNFPA 13hydraulic demand

Model Builder → Fire calc → Supply vs demand graph

RelatedNFPA-13 §28.4 form templates

Hazard coverage-cap warning (§11.2.3)

Flags a sprinkler layout whose spacing × coverage area exceeds the NFPA-13 §11.2.3 cap for the selected occupancy hazard class, catching an over-spaced head before it becomes a code violation instead of after.

coverage cap§11.2.3occupancy hazardspacingNFPA 13warning

Model Builder → Sprinkler layout

most remote areadesign areaiterative searchsolve-in-the-loopNFPA 13governing area

Iterative most-remote-area finder

Searches candidate design areas with a real solve in the loop to identify the hydraulically governing NFPA-13 area of application, then reports sprinkler demand from that governing area alone — rather than assuming the geometrically farthest area is always the worst case.

Model Builder → Fire calc → Find most remote area

Active/inactive sprinkler highlighting

Renders sprinklers inside the applied governing NFPA-13 design area visually distinct from the rest of the system, so it's immediately clear which heads are flowing in the reported case and which are not.

active sprinklerinactive sprinklerdesign areahighlightingvisualizationNFPA 13

Model Builder → Fire calc → Design area

Fire-mode forced Hazen–Williams solve

Enforces the NFPA-13 Table 22.4.4.7 per-pipe C-factor whenever a network is solved in fire mode, so a fire-protection network can't silently escape onto a Darcy–Weisbach friction model the code doesn't recognize.

Hazen-WilliamsTable 22.4.4.7C-factorfire modeNFPA 13friction model

Model Builder → Project Settings → Friction model (fire mode)

Relatedfriction models

Calculators — Pipe Flow & Pressure

Fast single-tool answers for velocity, pressure drop, friction, and open-channel flow.

Liquid pipe velocity

Size a pipe from flow, or find the acceptable flow range for a size, checked against service and erosional-velocity limits (API 14E).

pipevelocityAPI 14Esizingliquid

/calculators/liquid-pipe-velocity

Pressure drop

Compute pipe ΔP including fittings and valves (Darcy–Weisbach + ΣK·½ρv²), with a ±2 pipe-size comparison to see the effect of resizing.

pressure dropDarcy-Weisbachminor lossfittingspipe

/calculators/pressure-drop

Moody / friction-factor explorer

Read the Darcy friction factor from Reynolds number and relative roughness, comparing Colebrook against Swamee–Jain and reading the Moody chart directly — with the Darcy-vs-Fanning trap called out.

MoodyColebrookfriction factorReynoldsroughness

/calculators/moody-friction-explorer

Minor loss / equivalent length

Compare fitting loss three ways — Crane TP-410 (K, L/D), Hooper 2-K, and Darby 3-K — with total ΣK, equivalent length, and pressure drop for a fitting set.

minor lossK factorequivalent lengthCrane TP-4103-K

/calculators/minor-loss-equivalent-length

Air-duct sizing

Size round and rectangular HVAC ducts for ΔP, velocity, and Reynolds number (Huebscher equivalent diameter), checked against ASHRAE / SMACNA velocity limits.

air ductHVACASHRAESMACNAduct sizing

/calculators/air-duct

Open-channel Manning

Compute uniform open-channel flow in circular, rectangular, or trapezoidal sections with Manning’s equation, plus Froude number and flow regime.

open channelManningdrainageFroudenormal depth

/calculators/open-channel-manning

Line blockage / bottleneck back-calculation

Invert two gauge readings and one flow on a known line: compare the measured friction against the clean-bore prediction (the shared Darcy–Weisbach engine) and read the excess BOTH ways — an effective inner diameter from a bisection with roughness held, and an equivalent added K read against Crane benchmarks — with a ±5 % measurement band. Refuses to diagnose when the reading shows less loss than clean physics allows.

blockagefoulingtroubleshootingeffective diameterback-calculation

/calculators/line-blockage-diagnosis

Plumbing demand (Hunter’s curve)

Estimate a building’s peak water demand from fixture units via Hunter’s probability curve (IPC / ASPE), then size the water-service main.

plumbingHunterfixture unitIPCbuilding services

/calculators/plumbing-demand-hunter

Non-Newtonian pipe flow

Get ΔP, regime, and head loss for power-law, Bingham-plastic, and Herschel–Bulkley fluids (Metzner–Reed, Buckingham–Reiner, Dodge–Metzner) for muds, sludges, and pulp.

non-NewtonianBinghamdrilling mudsludgerheology

/calculators/non-newtonian-pipe-flow

Settling-slurry hydraulics

Find deposit velocity (Durand–Condolios), hydraulic gradient (Wilson excess), settling velocity, and slurry viscosity for heterogeneous slurries in horizontal pipe — for mining, dredging, and sand transport.

slurryDurandWilsondeposit velocitymining

/calculators/settling-slurry

Air receiver & compressed-air system

Size the air receiver from both governing cases (load-unload switching + peak-event storage) rounded to a standard shell, get the condensate load the receiver and dryer must handle (ASHRAE psychrometrics at receiver pressure), and size the air main with velocity/ΔP verdicts at line-pressure density.

air receivercompressed aircondensateair mainCAGI

/calculators/air-receiver

Calculators — Pumps & NPSH

Operating-point and cavitation-margin checks for pump selection.

Pump sizing (NPSH + system curve)

Find the operating point where the pump curve meets the system curve, and assess cavitation risk from NPSH available versus the pump’s NPSH required.

pumpNPSHsystem curveoperating pointcavitation

/calculators/pump-sizing

NPSH available & cavitation margin

Compute NPSH available from the full suction path (atmospheric/gauge pressure − vapor pressure ± static head − friction) against NPSH required per ANSI/HI 9.6.1, with a cavitation-margin warning and sensitivity plot.

NPSHcavitationsuctionANSI HIpump

/calculators/npsh-available

Pump health diagnosis (field troubleshooting)

Turn what a technician can actually measure — suction/discharge gauges with their elevations, a flow reading and clamp-meter power — into measured head, live efficiency and NPSHa, then rank seven probable causes (wear, cavitation, run-out, recirculation, low speed, viscosity) with what to check next. Every threshold is shown, a rule with missing inputs says so instead of being skipped, and a reading above 1.05× the pump curve REFUSES the diagnosis and sends you back to the gauges.

pump troubleshootingdiagnosishead deficitpump efficiency testcavitationwear ringclamp meterfield test

/calculators/pump-diagnosis

RelatedPump sizing NPSH available

Motor & pump energy audit (throttle loss, trim vs VFD)

Read the electricity bill for a running pump instead of its gauges. A clamp meter and the nameplate give input power, the motor loading (solved as a fixed point against the IE-class part-load curve, which is disclosed as generic), pump and wire-to-water efficiency, and the power burnt in the control-valve trim priced in ฿/yr. Impeller trim and a VFD are then presented ranked by payback, with the VFD saving taken from where the affinity-scaled pump curve actually meets the system curve — the cube law is printed beside the honest figure only so the gap is visible, never used to quote a saving. Three structural gates: an implausible efficiency deletes every ฿ figure and hands back a measurement checklist, an estimated power factor turns every ฿ into a band, and a blank static head removes the VFD card entirely rather than defaulting it to zero.

energy auditpump energymotor loadingthrottle lossVFD paybackimpeller trimwire-to-waterpower factoraffinity lawclamp meter

/calculators/motor-pump-energy-audit

Calculators — Relief & Safety

Pressure-relief sizing and overpressure protection to API and IEC codes.

Relief valve / PSV sizing (API 520)

Size a PSV/PRV orifice per API 520 Part I for gas/vapor, liquid, and steam service including choked flow and viscosity correction, then pick an API 526 letter size.

PSVrelief valveAPI 520API 526orificeoverpressure

/calculators/relief-valve

Thermal relief valve (API 521)

Size a thermal-relief PSV for a blocked, liquid-full line or vessel heated by sun, exchanger, or fire per API 521 §4.4.13, then choose the orifice and API 526 letter.

thermal reliefAPI 521PSVblocked-inoverpressure

/calculators/thermal-relief-valve

PSV inlet/outlet pressure drop

Check the API 520 Part II 3% inlet-loss and 16% built-up-backpressure rules (anti-chatter) and compute the reaction force for open discharge.

PSVAPI 520-IIinlet lossbackpressurereaction forcechatter

/calculators/psv-inlet-outlet-pressure-drop

PSV datasheet (API 520/521/526)

One form for a complete PSV rating: orifice selection, valve type, inlet/outlet drop, and reaction force, producing a single datasheet with an overall verdict.

PSVdatasheetAPI 526reliefRFQ

/calculators/psv-datasheet

Tank venting (API 2000)

Size breather / PV-valve vents for an atmospheric storage tank against thermal in/out-breathing, pumping, and fire cases per API 2000, and pick the governing case.

tank ventingAPI 2000breatherPV valvestorage tank

/calculators/tank-venting

Vessel depressurization / BDV sizing (API 521)

Simulate gas blowdown through a BDV orifice on both isothermal and adiabatic paths — check an existing orifice or size one for the API 521 §4.6.6 criterion (min(6.9 barg, 50% of initial) within 15 min), with P(t)/T(t) charts, peak flare load, and a cold-temperature MDMT warning.

blowdowndepressurizationBDVAPI 521flare loadMDMTbrittle fracture

/calculators/vessel-depressurization

Hazardous-area classification (IEC 60079)

Classify Zone 0/1/2 around a gas or flammable-liquid release per IEC 60079-10-1, computing release rate, zone radius, and recommended Ex marking, gas group, and temperature class.

IEC 60079hazardous areaExZone 0/1/2ATEX

/calculators/hazardous-area-classification

Calculators — Gas & Steam

Compressible-flow sizing and steam / condensate thermodynamics.

Compressible gas / steam pipe

Size gas and steam pipe for ΔP, velocity, and Mach number per Crane TP-410 (isothermal, Weymouth, Panhandle A/B) with a PR-EOS Z-factor and choked-flow check across 10 species.

compressiblegas pipesteam pipeCrane TP-410MachWeymouth

/calculators/compressible-pipe

Process blower rating

Find outlet temperature, adiabatic/polytropic head, and brake power for a blower from flow, pressure ratio, and gas properties (GPSA / API 617), with a recommended motor.

blowerGPSAAPI 617polytropic headbrake power

/calculators/blower-rating

Steam tables (IAPWS-IF97)

Look up h, s, v, ρ, u, and Cp for water and steam per IAPWS-IF97 across saturated, wet, subcooled, and superheated states — for boiler, turbine, and refrigeration work.

steam tablesIAPWS-IF97enthalpyentropyboiler

/calculators/steam-tables

Condensate load & flash steam

Compute flash-steam fraction on pressure let-down and condensate load (warm-up + running) using IAPWS-IF97 properties, per the Spirax-Sarco / TLV method.

condensateflash steamsteam trapSpirax-SarcoIAPWS

/calculators/condensate-flash-steam

Steam line designer (workflow)

Run a new steam main in one sequential workflow: line size from velocity + ΔP verdicts, insulation heat loss with the 60 °C surface check, condensate load, trap sizing at SF=2 with drip-leg guidance, and the flash-steam return line — Spirax-Sarco/TLV method on IAPWS-IF97 properties.

steam maininsulationsteam trapflash steamcondensate returnSpirax-Sarco

/calculators/steam-line-designer

Condensate stall diagnosis (stall chart)

Diagnose why a modulating-steam heat exchanger floods at turndown: the AMTD stall chart (jacket pressure vs load), the stall load L% where jacket pressure meets the condensate back pressure (header + lift head), the sub-atmospheric region, condensate rate at the stall point as the pump-trap capacity, and the ranked fixes with the vacuum-breaker condition stated either way.

stallstall chartcondensatepump trapvacuum breakerwaterhammerheat exchangerSpirax-SarcoTLV

/calculators/condensate-stall

Isothermal gas blowdown

Depressurize a vessel through an orifice with an isothermal blowdown ODE — pressure-vs-time and vent duration for a gas volume being blown down.

blowdowndepressurizationvesselventisothermalAPI 521gas

API: POST /blowdown

Relatedgas-line transient

Calculators — Heat & Thermal

Heat-exchanger sizing, transient thermal response, and moist-air properties.

Heat exchanger (LMTD + ε-NTU)

One tool, two questions: size the area with LMTD (A = Q/(U·F·ΔT_lm)) or rate performance with ε-NTU to get effectiveness and outlet temperatures — switchable on one page.

heat exchangerLMTDe-NTUeffectivenesssizing

/calculators/heat-exchanger

Heat-exchanger fouling diagnosis (field troubleshooting)

Diagnose a running exchanger from one field test point: it first checks the two sides against each other and REFUSES the whole diagnosis above 15 % heat-balance error, then gives actual U vs clean, the fouling factor consumed against the design allowance, a signature verdict separating fouling from a bypass or one-side flow maldistribution, and a linear clean-by date projected from two user-dated tests.

foulingheat exchangerRfcleaning schedulediagnosisheat balance

/calculators/hx-fouling-diagnosis

Cool-down / heat-up time

Estimate the time for a pipe, tank, or sphere to reach a target temperature with a lumped-capacitance model, with a Biot-number validity check and a cooling curve.

cool-downheat-uplumped capacitanceBiottransient thermal

/calculators/cooldown-time

Psychrometric properties

Find every moist-air property from any input pair (T_db + RH / T_wb / T_dp / W) using Hyland–Wexler per ASHRAE, with a psychrometric chart — for AHU and coil work.

psychrometricmoist airASHRAEhumidityHVAC

/calculators/psychrometric

Gas-liquid agitator (Rushton)

Compute ungassed/gassed agitation power, mass-transfer coefficient kLa (Van’t Riet), gas-dispersion regime, and hold-up for an aerated stirred tank, with a vendor RFQ datasheet.

agitatorRushtonkLaVan’t Rietmass transfermixing

/calculators/gas-liquid-agitator

Calculators — Vessels & Structural

Wall-thickness / MAWP to pressure codes, vessel volume, and separator sizing.

Pipe wall thickness / MAWP (ASME B31.3)

Compute minimum straight-pipe wall thickness under internal pressure per ASME B31.3 with corrosion and mill-tolerance allowances, checking a chosen schedule and finding MAWP.

ASME B31.3wall thicknessMAWPpipepressure

/calculators/pipe-wall-thickness

Pressure-vessel thickness (ASME VIII Div.1)

Compute minimum shell and head thickness (ellipsoidal / torispherical / hemispherical) and MAWP per ASME BPVC Section VIII-1 UG-27 / UG-32.

ASME VIIIpressure vesselshellheadMAWP

/calculators/pressure-vessel-thickness-asme-viii

Vessel volume & level

Convert level to liquid volume (or back) in horizontal/vertical vessels with flat, 2:1 ellipsoidal, hemispherical, or torispherical heads via closed-form Jones (1974) equations, with a dip/strapping curve.

vessel volumelevelJones 1974strappingtank

/calculators/vessel-volume-level

Gas-liquid separator (KO drum)

Size a knock-out drum / separator with the Souders–Brown equation (GPSA / API 12J), for vertical or horizontal orientation with pressure K-derating and mist-pad effect.

separatorKO drumSouders-BrownGPSAAPI 12J

/calculators/gas-liquid-separator-koy

Calculators — Instruments & Metering

Control-valve Cv, flow-meter sizing, and restriction orifices.

Control valve Cv (liquid)

Size a liquid control valve Cv/Kv per ISA-75.01.01 / IEC 60534 with choked-flow, cavitation σ, valve authority, and installed-characteristic checks for globe, ball, butterfly, and V-port trims.

control valveCvISA 75IEC 60534cavitation

/calculators/control-valve-cv

Gas control valve Cv

Size a control valve for gas/vapor service per ISA-75.01.01 (IEC 60534) with the expansion factor Y and choked-flow check — the compressible complement to the liquid valve tool.

gas control valveCvISA 75expansion factorchoked flow

/calculators/gas-control-valve-cv

Control valve complaint diagnosis

The inverse of sizing: enter the INSTALLED valve (rated Cv + inherent characteristic) and today's P1/P2/flow, and the tool locates where it is actually operating — implied opening % from the travel inversion, cavitation σ, flashing, choked flow, valve authority β — then names the complaint's cause: oversized, undersized, cavitating, flashing, or "the pipe is the problem". Refuses impossible readings rather than guessing.

control valvetroubleshootingdiagnosisoversized valvehuntingcavitationflashingvalve authorityISA 75

/calculators/control-valve-diagnosis

Orifice / nozzle / Venturi meter (ISO 5167)

Size a differential-pressure flow meter per ISO 5167 with the Reader-Harris/Gallagher discharge coefficient, gas expansibility, permanent loss, and uncertainty propagation for orifice, nozzle, and Venturi.

orifice meterVenturinozzleISO 5167flow measurement

/calculators/orifice-meter

Restriction orifice (ISO 5167)

Size a restriction orifice that must drop a target permanent pressure at a given flow — liquid (Bernoulli) and gas (choked/sub-critical per Crane TP-410 + ISO 5167), with cavitation check and multi-stage split.

restriction orificeISO 5167ROpressure let-downmulti-stage

/calculators/restriction-orifice

Storage tank designer (API 2000)

Design an atmospheric storage tank end-to-end from duty: working/nominal volume and D×H geometry, API 2000 normal venting (shared tank-venting engine), a nozzle schedule with velocity verdicts, gravity + pumped emptying time, and an RFQ summary card.

storage tankAPI 2000nozzle scheduledrain timebuffer tank

/calculators/storage-tank-designer

Weir / flume flow meter

Measure open-channel flow from head H over rectangular, V-notch, and Cipolletti weirs (ISO 1438) and Parshall flumes, with an inverse H↔Q mode and rating curve.

weirflumeISO 1438Parshallopen channel

/calculators/weir-flume-flow-meter

Calculators — Fluid Properties

Property lookup for pure and mixed fluids from the same database the solver uses.

Fluid properties (FDB 1,000+)

Look up ρ, μ, Cp, k, vapor pressure, and Pr for pure fluids from the 1,000+ fluid database (the same one used in the model builder) or blend components for mixture properties (Amagat / Grunberg-Nissan / Raoult).

fluid propertiesFDBdensityviscositymixture

/calculators/fluid-properties

Process Safety (PHA / HAC)

Full process-hazard-analysis workspace — HAZOP, LOPA, SIL, fault/event trees, bow-ties, and hazardous-area schedules.

PHA studies workspace

Run a multi-node hazard study with a worksheet schedule, a cross-study recommendations register, and PDF/CSV/JSON export — the home base for a full process-hazard analysis.

PHAHAZOPworksheetstudyprocess safety

HAZOPWhat-IfFMEAChecklistRPNmethodology

Four PHA methodologies

One worksheet engine supports HAZOP (parameter × guideword), What-If free-text, FMEA (RPN + Action Priority), and Checklist studies, so you can pick the right method per node without switching tools.

SILIEC 61508PFDavgSIFfunctional safetyarchitecture

SIL verification (IEC 61508)

Verify a safety instrumented function against both the PFDavg target and the architectural-constraint (SFF/HFT) cap per IEC 61508, with series subsystems, 1oo2D, spurious-trip rate, and proof-test optimization.

LOPAIPLriskCCPSprotection layer

LOPA (layer of protection analysis)

Credit independent protection layers against an initiating-event frequency to check whether a scenario’s risk is tolerable, tied directly to the safeguards on each deviation.

/pha-studies → Safeguards / LOPA

Fault-tree & event-tree analysis

Build fault trees — top-event probability plus enumerated minimal cut sets and the AND/OR Boolean logic behind a failure — and event trees that branch an initiating event through successive safety functions into all 2^k outcome paths, as drawer tabs on a deviation.

fault treeFTAevent treeETAminimal cut setstop eventboolean logicinitiating eventoutcome branchingreliability

/pha-studies → deviation → Fault/Event tree

Bow-tie diagrams

Visualize threats, the top event, consequences, and the preventive/mitigative barriers between them as a bow-tie built from the deviation’s own data.

bow-tiebarrierthreatconsequencerisk visualization

/pha-studies → deviation → Bow-tie

Curated hazard library & node templates

Pull from ~140 indexed causes, consequences, and safeguards tagged by parameter × guideword × equipment, and seed a node from equipment HAZOP / checklist templates — so studies start fast and stay consistent.

hazard librarynode templatecauseconsequencesafeguard

/pha-studies → deviation drawer

Recommendations / action register

Track recommendations across every study with owner, status, and overdue filters, inline status editing, CSV export, and a management-of-change (MoC) import that applies batched action-status updates — so nothing falls through the cracks after the workshop.

action registerrecommendationstrackingowneroverdueMoC import

/pha-studies/recommendations

HAZOP deviation evaluator

A single-deviation calculator that runs IEC 61882 + CCPS LOPA + IEC 61511 SIL-gap logic and produces an FM-EN-17 PHA datasheet — a quick standalone alternative to the full workspace.

HAZOPLOPAIEC 61882IEC 61511datasheet

/calculators/hazop-deviation

Hazardous-area project (SoRS)

Manage a multi-source Hazardous Area Classification project and build a 31-column Source-of-Release Schedule per IEC 60079-10-1 / EI 15 / API RP 505, exporting CSV/PDF with a datasheet per source for the electrical team.

HACSoRSIEC 60079source of releasearea classification

/projects/hac

PHA methodology & validation dossier

A live-computed, drift-proof dossier documenting the methodology and validation behind the SIL / FTA / ETA math, printable to PDF for audit.

validationmethodologydossierauditfunctional safety

/pha-studies/validation

PHA version history & snapshot diff

Every study keeps a revision timeline; snapshot any point and diff two snapshots to see exactly what changed across nodes, with a CSV export of the difference. Change control for a hazard study.

version historysnapshotdiffcomparerevisionchange controlMOC

sharingcollaborationnotificationsreal-timemulti-userteam

PHA sharing, notifications & live collaboration

Share a study with teammates, get a notification feed for shares / edits / locks, and co-edit over a live WebSocket connection — shared-by-me and shared-with-me views included.

/pha-studies/notifications

HMAC-signed audit trail

A tamper-evident, HMAC-signed audit log of every study action, verifiable and exportable — cross-study or per-study — so the record of who changed what, when, holds up to scrutiny.

audit trailHMACtamper-evidentcompliancerecord integritytraceability

/pha-studies/audit

Relatedcorrectness & honesty

E-signature sign-off workflow

Define sign-off requirements per study, capture electronic signatures, and issue signable datasheet evidence artifacts — a formal approval workflow for a completed hazard study.

e-signaturesign-offapprovalworkflowevidencedigital signature

IEC 61508-3tool qualificationT2assessorfunctional safetyevidence packcertification

IEC 61508-3 Tool Qualification Pack

A printable, assessor-ready evidence pack for tool qualification under IEC 61508-3 §7.4.4, recomputed live from the engine — a distinctive functional-safety deliverable few tools produce.

/pha-studies/qualification

Relatedvalidation dossier

Bulk CSV import for PHA / HAC

Seed a PHA or HAC study from a spreadsheet — an idle → parse → preview → submit CSV import pipeline that turns existing worksheets into study rows without hand re-entry.

CSV importbulkspreadsheetPHAHACmigrationonboarding

searchcross-studyglobal searchPHAfull-textportfolio

Relatedinteroperability

Global cross-study PHA search

Search every study and every worksheet row at once from the workspace header — a case-insensitive lookup across the whole PHA portfolio, so a hazard raised in one study is findable from any other.

/pha-studies → header search

Open-PHA JSON import

Bring a HAZOP study in from the Open-PHA interchange format with a parsed row preview before committing — the import counterpart to the Open-PHA export, so studies can move both directions.

Open-PHAimportHAZOPinterchangeJSONmigration

/pha-studies → Import → Open-PHA JSON

Relatedexports

Row-level comment threads

Open a worksheet row and discuss it in a threaded comment feed — replies, soft-delete, and moderation — so review conversation lives on the exact deviation it concerns instead of a separate email chain.

commentsthreadscollaborationreviewdeviationdiscussion

/pha-studies → open a row → comments

Configurable risk & tolerability matrix

Edit the study’s risk matrix itself — severity and likelihood labels and the band grid — and the per-severity tolerable target frequencies (with a reset to standard CCPS values), so the risk framework matches your corporate standard rather than a fixed default.

risk matrixtolerabilitytolerable frequencyCCPSconfigurableLOPA

/pha-studies → study settings → Risk matrix

Saved views & column presets

Save named filter-and-sort views of the worksheet and choose which columns show — so a large study can be sliced to the rows and fields a given review pass cares about and recalled instantly.

saved viewscolumn presetsfilterworksheetviewproductivity

/pha-studies → worksheet → Saved views

HAC bulk source operations

Select any set of release sources in a Hazardous Area Classification schedule and bulk-edit shared fields (grade, ventilation, safety factor, equipment type), bulk-delete, or seed the schedule from a CSV — instead of editing dozens of sources one by one.

HACbulk editbulk deleteCSV importsource of releaseschedule

/projects/hac → schedule → select rows → Bulk edit

Relatedhazardous-area project (SoRS)

HAC source revision history & diff

Every release source keeps a revision history you can open, diff two revisions field-by-field (before/after, changed cells highlighted), and restore an earlier revision — change control down to the individual source.

HACrevision historydiffcomparerestorechange control

/calculators/hazardous-area-classification → source (project mode) → Revision history

HAC completeness gate & sign-off

Before a Hazardous Area schedule can be issued it must pass a completeness check — required and recommended items are listed and required gaps block issuing — and a Made / Checked / Approved / Issued sign-off strip records who signed. A stale-calc banner flags sources computed on an older engine version.

HACcompletenessissuesign-offgatestale calclifecycle

/projects/hac → Issue…

Risk matrix widget

Pick likelihood and severity directly on a click-to-select risk matrix grid, with the marker landing on the resulting risk band in real time — a visual companion to the LOPA math on every deviation.

risk matrixlikelihoodseverityrisk rankingCCPSvisualization

/pha-studies → deviation → Risk matrix

RelatedLOPA

Unmitigated vs. mitigated risk cards

Shows the risk band before and after safeguard credit side by side with risk-band badges, so the value each independent protection layer buys is visible at a glance instead of buried in a probability number.

risk bandunmitigated riskmitigated risksafeguard creditLOPA

/pha-studies → deviation → Safeguards / LOPA

RelatedLOPA

Personal hazard library

Save your own reusable cause / consequence / safeguard entries to a private per-user library, separate from the curated ~140-entry set, so judgment calls from past studies carry forward instead of being retyped.

hazard librarypersonal librarycauseconsequencesafeguardreuse

/pha-studies → deviation drawer → My library

Relatedcurated hazard library

SIL PFDavg calculation (IEC 61508-6)

Computes average probability of failure on demand per IEC 61508-6 Annex B from component failure rates, proof-test interval, and diagnostic coverage — the core low-demand SIL number behind a safety instrumented function.

SILPFDavgIEC 61508-6Annex Bprobability of failure on demand

SILIEC 61508-2Route 1HSFFHFTarchitectural constraint

Relatedarchitectural constraint cap

SIL architectural-constraint cap (Route 1H)

Caps the achievable SIL against the IEC 61508-2 Route 1H safe-failure-fraction / hardware-fault-tolerance table for Type A and Type B elements, so a good PFDavg number can never silently overclaim a SIL the hardware architecture doesn't support.

SILseries subsystemPFDavgSIF architecturesensor logic final element

RelatedPFDavg calculation

SIL series-subsystem architecture

Models a SIF as an arbitrary chain of series subsystems (sensor / logic solver / final element and beyond), summing PFDavg across the chain while capping each subsystem to its own architectural constraint — matching how a real SIF is actually assembled.

/pha-studies → SIF verification → Subsystems

Related1oo2D voting architecture

1oo2D voting architecture

Quantifies a 1oo2D (one-out-of-two with diagnostics) voted subsystem with Hokstad-form conservative-bound math, cross-checked against an independent numerical Markov model — for redundant final elements or logic solvers.

1oo2Dvoting architectureHokstadredundancyMarkov modelSIL

/pha-studies → SIF verification → Subsystems

Spurious-trip rate (STR / MTTF)

Estimates the spurious-trip rate and mean-time-to-failure-spurious for a SIF architecture, so a safety upgrade's cost in unwanted shutdowns is visible alongside its PFDavg benefit.

spurious tripSTRMTTFnuisance tripavailabilitySIL

partial stroke testproof test intervalPTCoptimizationSILmaintenance

Partial-stroke testing & proof-test-interval optimizer

Models the imperfect-coverage residual left by partial-stroke testing between full proof tests, and searches for the proof-test interval that meets a PFDavg target — turning 'how often do we test' into a calculated answer.

FMEDAfailure ratediagnostic coveragelambda Dcomponent librarySIL

Curated FMEDA failure-rate library

Pre-fills a SIF component's failure rate (λD) and diagnostic coverage from a curated, versioned FMEDA dataset instead of starting from a blank field, with indicative-vs-user-supplied provenance kept visible.

/pha-studies → SIF verification → Load from FMEDA

RelatedFMEDA CSV import

FMEDA CSV import with certified provenance

Imports a vendor's FMEDA report as CSV and tags it certified-tier evidence, distinguishing vendor-certified failure data from the platform's own indicative curated library at a glance.

FMEDACSV importcertifiedvendor dataprovenanceSIL evidence

/pha-studies → SIF verification → Import FMEDA

Relatedcurated FMEDA library

SIF subsystem architecture builder

An interactive editor for assembling a SIF's subsystem architecture — voting, component counts, per-subsystem failure data — with the result persisted against the safeguard it verifies.

SIFsubsystemarchitecture buildereditorSILvoting

/pha-studies → SIF verification → Subsystems

Methodology citation registry

Every PHA/SIL screen and report cites the standard behind its math inline — IEC 61882, IEC 61508, CCPS LOPA and more — so a reviewer can trace a number back to its clause without leaving the tool.

citationIEC 61882IEC 61508CCPSstandards traceability

/pha-studies (inline on every screen)

Relatedvalidation & methodology dossier

Action lifecycle & revalidation (MoC)

Takes a recommendation beyond a status flag through a full lifecycle workflow with revalidation hooks, so a management-of-change trigger can reopen and re-verify an action rather than quietly closing it.

action lifecyclerevalidationmanagement of changeMoCrecommendation workflow

/pha-studies/recommendations

Relatedaction register

P&ID viewer with pinned annotations

Attaches a P&ID image to a study and pins click-placed annotations directly on it against specific equipment, so a HAZOP node's discussion stays anchored to the actual drawing instead of a separate list.

P&IDpiping and instrumentation diagramannotationdrawing reference

/pha-studies → study → P&ID

Seed HAZOP from a solved hydraulic model

Generates starter HAZOP deviations directly from a solved Model Builder network, node by node, so a hazard study can begin from the actual design-basis numbers instead of a blank worksheet.

seed HAZOPmodel builderdesign basisauto-populatebridge

Model Builder → element results → Send to PHA

Hydraulics → PHA → SIL → datasheet bridge

Carries a solved network's design-basis numbers through a PHA study into a SIL-verified safeguard and out to a signed datasheet in one traceable thread, instead of four disconnected tools kept in sync by hand.

end to enddesign basistraceabilityPHASILdatasheet bridge

Model Builder → PHA study → SIF verification → Datasheet

Regulatory framework mapping

Cross-references a study's hazards and safeguards against OSHA PSM's 14 elements, Seveso III, and RAGAGEP as an indicative appendix, helping a study demonstrate regulatory coverage without a separate compliance exercise.

OSHA PSMSeveso IIIRAGAGEPregulatory mappingcompliance appendix

/pha-studies → Export → Regulatory appendix

Public cross-method SIL benchmark

Live-recomputes the platform's SIL math against the published Brissaud & Oliveira (2015) benchmark across six SIF architectures and embeds the comparison in the validation dossier — an independently checkable credibility anchor, not a self-graded claim.

benchmarkBrissaud Oliveiracross-checkvalidationSILpeer-reviewed

/pha-studies/validation

Relatedvalidation & methodology dossier

Demo HAZOP study seeder

Seeds a ready-made demo HAZOP study with populated deviations and safeguards on first login, so a new user can explore the worksheet, LOPA, and SIL views without building a study from scratch first.

demoonboardingsample studygetting started

/pha-studies (new account)

Parking-lot panel

Captures deferred items and off-topic ideas raised during a HAZOP workshop in a panel alongside the worksheet, so the session keeps moving without losing the thought.

parking lotdeferred itemsworkshop facilitationHAZOP session

/pha-studies → study → Parking lot

Records & Compliance (21 CFR Part 11)

Tamper-evident records and signed sign-off workflows, modeled on 21 CFR Part 11 electronic-records/electronic-signature practice.

Audit trail viewer & verification API

Browse a study's tamper-evident audit chain in a filterable, load-more dialog with a live chain-integrity verify badge, and pull the same evidence via a list/verify/export API for external tooling.

audit trailviewerverifyAPI21 CFR Part 11chain integrityevidence export

/pha-studies → Audit Trail

RelatedHMAC-signed audit trail

Org-admin audit-events export

Stream a CSV export of every audit event across an organization's studies via the API, with the correct row-level-security context recaptured per row — a cross-study evidence pull for compliance reviews. Available over the API today; a dedicated admin page is not yet built.

audit eventsorg adminstreaming exportCSVcompliancerow-level security

API: org audit-events CSV export

Freeze-on-first-signature

The moment the first required signer signs off, a study's content becomes read-only study-wide — so a signed record can never be silently altered underneath its own approval.

freezeread-onlysignaturerecord integrity21 CFR Part 11immutability

/pha-studies → sign-off

Relatede-signature sign-off workflow

Signatures export appendix

Every signed study's PDF/Word export carries a dedicated Signatures section listing each signer, role, timestamp, and a hash-prefix — so the paper trail travels with the document, not just the database.

signaturesexportPDFWordappendixevidence21 CFR Part 11

write lockissued409immutabilityserver-side enforcementrecord integrity

Issued-study write lock

Once a study is issued, every content-write endpoint returns a hard 409 on further edits — a server-side lock that can't be bypassed from the UI, closing the gap between 'signed' and 'actually immutable'.

/pha-studies (post-issue)

Part 11 records & signatures dossier

A dedicated Records & Electronic Signatures section in the printable Validation & Methodology dossier documents the audit-chain and e-signature controls an auditor would ask about under 21 CFR Part 11.

21 CFR Part 11dossierelectronic recordselectronic signaturesauditcompliance

/pha-studies/validation

RelatedPHA validation dossier

Login lockout & rate limiting

Five failed login attempts locks an account for 15 minutes, with IP-level rate limiting on the login endpoint — brute-force resistance for the credentials guarding your compliance records.

/login

Datasheets & Reporting

Turn a calculation into a vendor-ready RFQ datasheet or an exportable report in the format your team already uses.

FM-EN-17 RFQ datasheets

Generate A4, print-ready vendor RFQ datasheets from 23+ spec builders (pump, PSV, blower, agitator, flare, strainer, and more) with cover, revision history, operating conditions, and calculation pages.

datasheetFM-EN-17RFQvendorspec sheetA4

Any calculator → Datasheet

Calculation sheets

Produce a transparent calculation sheet showing inputs, equations, and results for a calculator or a selected builder element — the audit trail behind a number.

calc sheetcalculation reportaudittransparency

Calculators / Model Builder → Calc sheet

Exports — PDF, Word, Excel, CSV, JSON

Export PHA studies and results as a FM-EN-17 PDF, a true .docx (Word), a true .xlsx (Excel), CSV, or JSON — including the Open-PHA interchange format — so deliverables drop straight into existing workflows.

exportPDFWorddocxExcelxlsxCSVJSONOpen-PHA

exportCSVresultsbuilderspreadsheet

Builder results export (CSV)

Export a solved network’s node and pipe results straight from the builder toolbar as a CSV — a quick hand-off of the numbers behind a solve into a spreadsheet, separate from the PHA study exports.

Model Builder → Export Results

Shared datasheet revision history

Keeps a persisted, shared revision history for a calculator or case-study datasheet across sessions and reviewers, so a Rev 0A vs. Rev 1 comparison is possible without exporting files back and forth.

revision historydatasheetpersistencecase studycollaboration

Any GB/admin datasheet → Revisions

RelatedFM-EN-17 RFQ datasheets

Datasheet issue & sign-off

Issues a calculator or case-study datasheet through a password re-authenticated sign-off flow that stamps a SHA-256 content hash, so a downstream reviewer can verify the issued sheet's chain is intact and untampered.

e-signaturedatasheet issueSHA-256content hashchain of custody

Any calculator → Datasheet → Issue

RelatedPHA e-signature workflow

Report export presets

One click swaps a report between Full-study, OSHA-PSM, Seveso-III, and Concise presets, each pulling the section set and depth that audience actually needs instead of hand-picking sections every time.

report presetOSHA PSMSeveso IIIexport template

/pha-studies → Export → Preset

Report section reorder & cover branding

Persists a per-study custom section order and column set, plus an accent-colour cover, so an exported report matches how your organization actually structures and brands a deliverable.

report customizationsection reorderbrandingcover page

/pha-studies → Export → Customize

Graphics embedded in exports

Embeds the risk-matrix heat-grid and bow-tie diagram as real images inside PDF and Word exports, so the visual risk story travels with the report instead of staying trapped on screen.

graphicsrisk heat gridbow-tie imagePDF exportWord export

honestyscope notecorrect or loudrefuseblockingwarningvalidation

Relatedexports

Correctness & Honesty

"Correct or loud" — instead of a silently-wrong number, the solver refuses, blocks, or warns when a case is outside its validated envelope.

Scope-note honesty register (steady)

A structured register whose codes run through A52 (roughly three dozen live detectors) watching every steady solve and raising refuse / blocking / warn / info notes — gating the datasheet when a result is not safe to use for sizing rather than handing back a plausible-but-wrong figure.

Model Builder → Run (Scope Banner)

Marching-engine honesty detectors

The marching multi-fluid engine adds its own post-solve honesty layer — eight structured detectors (free-water / three-phase separation, slugging on inclines, over-cooled vapor, single-MW flash drift, buoyancy loops, associating-species EOS limits, near-critical CO₂ viscosity, homogeneous tee splits) — surfaced on the same Scope Banner as the steady register.

honestymarchingscope notetwo-phasecorrect or louddetector

Model Builder → Run (Scope Banner)

Relatedsteady scope register

Transient honesty register (T-register)

The same refuse/block/warn discipline for the transient engine — e.g. it names why a multi-scenario run fell back to a legacy path, flags cavitation, and enforces a low-Mach envelope on gas transients — and it disables the transient result export dropdown whenever a blocking note fires, so a gated result can never be exported as if it were valid.

transientT-registerhonestyMOCscope notecavitationexport gating

Model Builder → Transient panel (Scope Banner)

Verification dossier

A published record of dozens of verification cases (through VC-073) cross-checking the engines against EPANET and FluidFlow references plus exact analytical oracles and published lab surge experiments, so you can see exactly where the numbers have been proven.

verificationvalidationEPANETFluidFlowexact oracleexperimentdossierbenchmark

/validation/dossier

Solver verification matrix

An in-app report of the EPANET-parity verification matrix — solve levels × case categories — showing at a glance which solver paths are benchmarked green.

verification matrixEPANET parityvalidationsolver routerbenchmark

/validation/solver-router

Relatedverification dossier

Live solver-layer demos

Two live in-app demos you can run yourself: a Tier-2 multi-fluid marching-network solve over canned compressible networks, and a Tier-1 thermodynamic fluid-layer demo (flash / phase detection plus heated-pipe marching with a quality-vs-position chart).

demovalidationnetwork layerfluid layermarchingflash

/validation/network-layer

Relatedfluid-layer demo

Friction-parity validation examples

A dedicated series of validation example networks — the 7.x set, from branch-tee manifolds through a fire sprinkler system, plus an API-521 flare header — you can load and solve to check friction-model parity against reference results, rather than hunting for them among the general examples.

validationfriction parityexamplebenchmarkflare header7.4

Model Builder → Toolbar → Validation examples

Relatedexamples library

Head-sanity convergence gate

Rejects a solved network state with a physically implausible head (e.g. thousands of meters negative) instead of handing it back as a converged answer — a numerical-nonsense trap, not just a slow-convergence one.

convergencehead sanitysolver honestycorrect or loudnumerical stability

valve huntingNewton iterationsolver stabilitycheck valveconvergence

Anti-hunting valve-status freeze

If a check or control valve's open/closed status flips back and forth for 5 consecutive Newton iterations, the solver freezes it rather than looping forever or oscillating to a fake convergence.

scenariobatch runhonestconvergencecorrect or loud

Honest scenario/batch runner

Every scenario in a batch run gets an independent, real solve — a scenario that fails to converge is reported FAILED, not silently folded in as converged alongside the ones that actually solved.

Model Builder → Tools → Scenarios

Specific solver-failure messages

A non-converging solve surfaces the engine's actual failure reason in the UI — which constraint or node broke down — instead of a generic 'solve failed' message that leaves you guessing what to fix.

error messagenon-convergencediagnosticssolver failurecorrect or loud

compressorhonest fallbackcorrect or loudgas modeerror handling

Honest compressor-mode fallback

An unsupported compressor setpoint or pressure-ratio request returns a clearly labeled non-converged reason instead of crashing with a server error, so an out-of-envelope case is visibly out of envelope.

gas networkconvergencemass balanceNewtoncorrect or loud

Gas-network convergence honesty

A gas-network solve is only called converged when both the Newton step is small AND the mass-balance residual is satisfied — closing a case where a tiny step alone had been reported as a false convergence.

relief deviceNewton stabilitytransientcorrect or loudconfiguration error

Relief-device Newton-stability guard

A relief or surge device configuration that would destabilize the transient Newton solve is caught and surfaced as a clear configuration error, instead of quietly returning a wrong transient result.

Model Builder → Surge Protection

Data-provenance statement (FMEDA)

Every SIL calculation carries a derived certified / indicative / user-supplied provenance status for its failure-rate data, surfaced as a gated 'FMEDA Data Provenance' section in the study export — so you know how much to trust the numbers behind the number.

provenanceFMEDASILdata qualitycertifiedindicativeexport

disclaimerindicativescreeninglabelingLOPAexport

RelatedSIL verification

Indicative/screening labeling

LOPA cards, the worksheet grid, and every Word/PDF export carry a consistent indicative-vs-certified disclaimer, so a screening-level estimate is never mistaken for a certified engineering result downstream.

Open-PHAexportdata losscorrect or loudinteroperabilityHAZOP

Open-PHA export data-loss gate

Exporting to the Open-PHA interchange schema (which only models HAZOP) refuses on FMEA or Checklist studies instead of silently dropping their content into a format that can't represent it.