FluidFlow — Pipe Network Analysis & Hydraulic Design Software
FluidFlow is pipe network analysis software for engineers who design, size, troubleshoot and optimize fluid piping systems. It performs steady-state hydraulic analysis of liquid, gas, two-phase, slurry, and non-Newtonian flows — calculating pressure drop, flow distribution, temperature profiles, and equipment operating points across complete pipe networks of any complexity.
Model the complete piping network — every pipe, pump, valve, fitting, and boundary condition — and FluidFlow performs a rigorous analysis of the entire system. The result is a true operating picture: pump operating points, valve authority, and where the network is likely to be constrained. That visibility helps engineers spot risks early and evaluate practical fixes before they become costly field surprises. FluidFlow makes the analysis fast, repeatable, and auditable.
What FluidFlow Solves: Pressure Drop, Flow Distribution & Fluid Transport Equipment Size
Each calculation module targets a specific flow behavior — liquid, gas, two-phase, slurry, or non-Newtonian. Activate only what your application requires — your selection can evolve as project scope changes. All modules include integrated heat transfer and scripting by default.
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System-Level Modeling Capabilities
Automatic Equipment Sizing
FluidFlow sizes key system components to support design, analysis, and troubleshooting — reducing manual iteration and helping you evaluate changes and reach optimised solutions faster:
Pipes — sized by economic velocity (balancing capital and energy costs), standard velocity, or pressure gradient
Pumps — auto-size based on defined flow or pressure rise to meet your required duty points
Control valves — preliminary Cv/Kv sizing and calculation of process data for manufacturers model selection
Relief valves and bursting discs — orifice area calculation for overpressure protection
Flow measurement devices — orifice plates, Venturi tubes, and flow nozzles with differential pressure and permanent pressure drop calculations
All sizing follows recognised industry standards. See the Standards Reference table at the end of this article.
Branching Network Analysis
Branched and parallel pipe networks are inherently complex to solve because flow and pressure interact across every connected path. FluidFlow solves complete pipe networks — including branched and parallel paths — to determine flow distribution, pressure profiles, and the system constraints that drive real operating behaviour.
Pump Curve Performance Analysis
FluidFlow helps you evaluate how a pump’s performance will behave in the system it is working with — showing the resulting operating point in terms of head, flow, efficiency, power, and NPSH.
This means FluidFlow finds the pump operating point (duty point) that balances with the system resistance using its performance curve. You can then check that the NPSH available provides adequate margin over the NPSH required, and identify potential issues such as excessive head, high velocities, or operation outside your intended operating range — before the pump is purchased.
Phase Detection
FluidFlow detects when local pressure and temperature conditions drive a phase change in pure Newtonian fluids (for example, flashing or condensing), so you can identify where two-phase behaviour may impact hydraulics and equipment performance.
Modelling Versatility
Use FluidFlow across a wide range of flow regimes and fluid types — including liquid, gas, two-phase gas-liquid, settling slurry, and non-Newtonian flow.
Model Any Fluid Transport Equipment
Model virtually any fluid transport equipment using FluidFlow’s wide selection of standard components, plus generic elements for custom losses, restrictions, and user-defined equipment. Pipes can be modelled with cylindrical, rectangular/square, or annular cross-sections, and you can represent real operating conditions by adjusting parameters such as pipe roughness to reflect corrosion, erosion, or scaling effects.
Back-Calculation
Reverses the normal calculation direction to determine unknown inputs from known outputs. Instead of iterating manually, you specify the target data — a required flow rate, an allowable pressure drop, a desired valve Cv — and FluidFlow determines what input achieves it.
Multi-Calc
Runs multiple scenarios across a single network model in parallel. Compare the effects of different operating conditions, equipment selections, or design parameters side by side without building separate models.
Calculation Modules
Liquids (Incompressible Flow)
Models single-phase liquid flow using established pressure drop methods:
Darcy–Weisbach with Colebrook-White friction factor — applicable across laminar, transitional, and turbulent flow regimes
Hazen–Williams — commonly applied in water distribution and fire protection systems under turbulent conditions
Shell–MIT — empirical method for high-viscosity hydrocarbon and heated transport systems
Fixed friction factor — for field or lab gathered data, legacy system matching, or sensitivity studies
Applicable systems — single-phase liquid pipe networks such as cooling water and utility systems, water distribution and firewater rings, hydrocarbon transfer lines, and pump suction/discharge piping
Gas (Compressible) Flow Analysis
Models gas flow using real-gas behavior and no isothermal or adiabatic assumptions, capture the expansion and temperature changes that occur as gas flows through the network:
Real gas equations of state (Peng–Robinson, Benedict–Webb–Rubin, Lee–Kesler) for accurate thermodynamic property evaluation
Joule–Thomson effect reflecting temperature change accompanying real gas expansion
Detection of choked (critical) flow at restrictions with correct mass flow limiting
Applicable to natural gas pipelines, compressed air, steam distribution, process gas networks, and relief system headers
Two-Phase (Liquid–Gas)
Models simultaneous liquid and gas flow using eight validated multiphase pressure drop correlations:
Beggs–Brill
Lockhart–Martinelli
Friedel
Chisholm–Baroczy
Müller-Steinhagen and Heck
Homogeneous Equilibrium Model (HEM)
Drift Flux Model
Automatic correlation selection (Whalley Criteria) — choose the Whalley option and FluidFlow will apply a selection criterion to automatically pick the most appropriate pressure drop correlation from Friedel, Chisholm–Baroczy, or Lockhart–Martinelli for the current flow conditions.
The module handles three Two-Phase flow scenarios:
Constant quality — fixed gas-to-liquid ratio along the pipe
Flashing flow — liquid vaporises as pressure drops below bubble point, with progressive quality tracking
Condensing flow — vapour condenses as temperature decreases along the flow path
Slurry and non-Newtonian
Models hydraulic transport of solid–liquid mixtures covering settling slurries, non-settling slurries, and non-Newtonian flows with pipe inclination effects.
Settling slurry correlations:
Durand
Wasp
WASC (Wilson - Addie - Sellgren - Clift)
Sellgren - Wilson Four-Component Model (2001)
Liu Dezhong
4CM (2022)
Vsm (1995)
V50 (1990)
Deposition velocity — calculates the minimum transport velocity to prevent stationary bed formation.
Pipe inclination corrections — configurable methods including Wilson–Tse 1984 and Extended Wilson–Tse Chart (2019) for deposition velocity adjustment in inclined pipelines.
Vertical pipe friction loss — dedicated methods including Vertical WASC, 4CM, and Spelay et al. collisional stress model.
Slurry Centrifugal pump derating — five methods including ANSI 2021 Monosize, GIW 4CM, HI Guidelines, King, and Fixed Reduction Ratio for predicting slurry pump performance within complete systems.
Non-Newtonian fluid models:
Power Law
Bingham Plastic
Herschel–Bulkley
Casson
Includes configurable yield stress definition with user-defined and calculated options, tabulated shear rate vs. shear stress data input, and R² reporting for viscosity model selection.
Pulp & Paper stock flow — models fibre suspension pressure losses using TAPPI and Moller K correlations for stock flow systems commonly found in pulp and paper manufacturing.
Heat Transfer
Integrated across all modules by default. Temperature changes along the network affect fluid properties at each calculation point:
Do heat loss — detailed pipe heat transfer calculations for heat loss or heat gain along the line
Buried pipe heat transfer accounting for soil conductivity and burial depth
Fixed heat transfer rate for specifying known duty directly
Fixed temperature change — specify a known ΔT across a pipe or section when outlet temperature change is known
Scripting
Pascal and Basic scripting for automating repetitive tasks, custom calculation sequences, and user-defined control logic. This feature is included at no extra cost with Liquid or Gas licences.
Transient Analysis — For liquid transient analysis, check our complimentary tool at flowdesigner.com or Contact Us to arrange access.
Built-In Databases
FluidFlow includes comprehensive reference data to reduce setup time and improve consistency, and you can expand these built-in databases with your own fluids, components, and equipment data:
Fluid database — over 1,200 fluids with thermodynamic and transport properties
Component database — over 800 fittings, valves, and piping components with resistance data
Booster database — manufacturer curves for pumps, blowers, fans and compressor direct selection and performance matching
Custom component library — create, save, and reuse proprietary equipment, custom fluids, and non-standard fittings
Usability
Short learning curve — most users are up to speed in a few hours. Build your first network in minutes. Free basic training on-demand covers software essentials with introductory theory on liquid, and gas modules.
Single unified workflow across all calculation modules — the same interface whether you are working with liquid, gas, two-phase, slurry, or pulp & paper stock
Interactive charts — pump curves, system curves, energy grade lines, and temperature profiles visualised within the model
Flowsheet chart tool — a chart available in the flowsheet toolbar for consolidating component calculation data into a single chart
PCF file import — import Piping Component Files from CAD tools (SmartPlant 3D, CADWorx, SolidWorks, Autodesk, and others) to build FluidFlow models directly from 3D designs
Excel integration — read input data from and write results to Excel for batch processing and reporting
Customisable reports — generate reports in PDF, Word, and Excel with company branding and standard formatting
Typical time savings — up to 80% faster than spreadsheet-based calculations and up to 40% faster than comparable software
Quality Assurance and Validation
Over 300 QA test networks maintained and validated against reference data
Verified against Crane Technical Paper 410, Idelchik, and Miller reference publications
Developed by an ISO 9001 certified team with continuous development since 1984
Used in 68+ countries across all industry sectors
Standards Reference
Application | Standard | Description |
Control valve sizing | ANSI/ISA-75.01.01 | Cv/Kv calculation and valve sizing methodology |
Flow measurement | ISO 5167-1:2003 | Orifice plates, Venturi tubes, and flow nozzles |
Relief valve sizing | API 520 Part 1 | Sizing and selection of pressure-relieving devices |
Relief valve sizing | ISO 4126 | Safety devices for protection against excessive pressure |
Industries
FluidFlow is used across every sector where fluid piping systems are designed, operated, or optimised:
Oil & Gas — production facilities, gas gathering, pipeline transport, relief systems, flare headers
Mining & Minerals — slurry pipelines, tailings transport, dewatering systems, thickener underflow
Water & Wastewater — distribution networks, pumping stations, treatment plant hydraulics, fire protection
Chemical & Petrochemical — process piping, reactor feed systems, cooling water, chemical dosing
Power Generation — steam distribution, condensate return, cooling systems, fuel gas supply
Pulp & Paper — stock flow piping, chemical recovery, white water systems
LNG & Cryogenics — liquefaction plant piping, BOG handling, cryogenic transfer, regasification
Pharmaceutical & Food — clean-in-place (CIP) systems, process transfer lines, utility piping
Shipbuilding — ballast systems, fuel oil transfer, fire-fighting mains, seawater cooling
And many more — FluidFlow is used in any industry where fluids flow through fully filled pipes and conduits.
Best Practices
In FluidFlow, best practice hydraulic modeling starts by thoroughly understanding the system and its design intent. Define clear requirements and a target level of accuracy, then build assumptions that match that accuracy without stacking arbitrary uncertainty margins that can quietly overdesign the network and drive unnecessary energy, operating, and capital costs.
Use FluidFlow’s productivity features to keep models consistent and auditable. Apply multiselection and component defaults to globally set inputs, maintain reusable equipment and piping specifications in databases, and represent non-standard items with generic resistances when geometry-based components are not applicable.
When using pump data, keep affinity-law adjustments within modest impeller trims (typically 10–20% or less) where geometric similarity still holds. When troubleshooting, address the largest drivers of error first since many minor discrepancies disappear once major issues are corrected.
Maximize the use of charts when analyzing systems. The Chart object in the flowsheet can be used to create double y-axis charts for more effective analysis and clearer interpretation of trends.
Use advanced productivity features such as Multi-Calc and back-calculation to expedite analysis by comparing scenarios quickly and solving for unknown inputs from defined target conditions.
When designing, it is not always about rigidly following a process standard or minimizing cost, but about making a rational engineering decision. In some cases, compliance to standards or intentional overdesign may be justified to balance other priorities such as safety, reliability, constructability, or environmental impact. For example, it may be acceptable to oversize a pipe slightly to protect a pump from cavitation and long-term wear, or to avoid the cost and procurement delays that arise when specifying non-standard pipe sizes simply to meet economic velocity criteria.
Get Started with FluidFlow
Free trial — full-featured evaluation
Free training — 5.5 hours of basic training included with every license
Talk to an engineer — our support team are practising engineers, not call-centre staff