AFT Pipe Flow Simulation Software Suite 2026 — Fathom, Arrow, Impulse & xStream

The AFT Product Suite at a Glance

All four AFT tools share a common codebase, a consistent interface, and compatible file formats. This means engineering teams can use multiple tools on the same project without relearning a new environment, and models can be transferred between tools — for instance, a Fathom steady-state model opens directly in Impulse for water hammer analysis without modification.

AFT Fathom — Steady-State Liquid and Low-Velocity Gas Systems

AFT Fathom is the industry-standard tool for calculating steady-state pressure drop and flow distribution in liquid piping and ducting systems. It answers the fundamental hydraulic design question: under normal operating conditions, what are the pressure, flow rate, and velocity at every point in the network?

Primary applications:

• Pump sizing and system curve analysis for centrifugal and positive displacement pumps
• Pressure drop and flow distribution across liquid distribution and process piping networks
• Heat transfer modeling in heat exchangers, jacketed pipes, and cooling systems
• Network balancing — tuning valves and orifices to hit target flows at each consumer
• Automated pipe sizing optimization with the ANS module
• Energy analysis and pump operating cost comparison across scenarios
• Control valve sizing and regulator setpoint evaluation

Industries served: water and wastewater, oil and gas, petrochemical, industrial HVAC, mining, pharmaceutical, food and beverage, power generation, data centers.

→ Full AFT Fathom product page — capabilities, 2026 features, and licensing:

AFT Arrow — Steady-State Compressible Gas and Steam Systems

AFT Arrow is the specialized tool for calculating steady-state pressure drop, flow distribution, temperature, and Mach number in compressible gas and steam piping systems. It handles the full range from subsonic through sonic choking — conditions where standard incompressible hydraulic tools produce incorrect results.

Primary applications:

• Pressure drop and flow distribution in natural gas transmission and distribution networks
• Steam header design and distribution analysis in power plants and industrial facilities
• Sonic choking evaluation at pressure reduction stations, orifices, and control valves
• Compressor, fan, and blower modeling with performance curve integration
• Energy optimization — comparing damper control versus variable speed drive strategies
• Gas mixture property handling for process gas and LNG applications
• Automated network sizing and goal seek with the ANS and GSC modules

Industries served: oil and gas, petrochemical, power generation, steel and metallurgy, aerospace, industrial HVAC, water and wastewater, engineering consulting.

→ Full AFT Arrow product page — capabilities, 2026 features, and licensing:

docrack.me/aft-arrow

AFT Impulse — Water Hammer and Pressure Surge in Liquid Systems

AFT Impulse is the specialized tool for water hammer and pressure surge transient analysis in liquid piping systems. Built on the Method of Characteristics (MOC), it tracks pressure waves, flow changes, and dynamic piping forces over time — from the moment a pump trips or a valve closes through wave reflections, cavitation events, and return to steady state.

Primary applications:

• Water hammer analysis following pump trips and valve closures in transmission mains and process systems
• Cavitation and column separation prediction using DVCM and DGCM models
• Sizing and placement of surge protection devices — surge tanks, gas accumulators, air and vacuum breaker valves
• Pump transient modeling with four-quadrant performance curves for reverse flow and reverse rotation conditions
• Check valve dynamics and slam assessment
• Transient force export to CAESAR II, AutoPIPE, TRIFLEX, and ROHR2 for pipe stress analysis
• Slurry water hammer with the SSL module; PD pump pulsation with the PFA module

Industries served: water and wastewater, oil and gas, petrochemical, power generation, mining, data centers, pharmaceutical, pulp and paper, engineering consulting.

→ Full AFT Impulse product page — capabilities, 2026 features, and licensing:

docrack.me/aft-impulse

AFT xStream — Compressible Transient Analysis in Gas and Steam Systems

AFT xStream is the specialized tool for compressible transient analysis in gas and steam piping systems — the gas-side equivalent of what Impulse does for liquids. Also MOC-based, xStream tracks pressure wave propagation, shock formation, choking, and heat transfer over time during emergency shutdowns, blowdowns, compressor trips, and startup sequences.

Primary applications:

• ESD and blowdown analysis in gas compression and processing facilities
• Steam system transient behavior during turbine trips and emergency valve closures
• Pressure wave and shock propagation in high-pressure gas headers
• Depressurization timeline prediction for blowdown system design
• Compressor startup and shutdown sequence verification
• Pulsation frequency analysis and acoustic resonance avoidance with the PFA module
• Real-gas property modeling for accurate high-pressure, high-temperature predictions

Industries served: oil and gas, petrochemical, power generation, aerospace, steel and metallurgy, EPC engineering consulting.

→ Full AFT xStream product page — capabilities, 2026 features, and licensing:

docrack.me/aft-xstream

Which AFT Tool Do You Need?

The selection comes down to two questions: what phase is your working fluid, and do you need steady-state or transient analysis?

Using Multiple AFT Tools on the Same Project

Many industrial facilities require more than one AFT tool. Common combinations include:

• Fathom and Impulse together: design and verify liquid system steady-state performance with Fathom, then confirm surge safety under all transient events with Impulse. Fathom files open directly in Impulse — no model recreation required.
• Arrow and xStream together: size and balance the gas or steam network at steady state with Arrow, then verify safe behavior during ESD sequences and blowdowns with xStream.
• Fathom and Arrow together: projects with both liquid and gas or steam systems — common in power plants, refineries, and petrochemical complexes where water, steam, and process gas networks coexist.
• All four tools: large EPC projects requiring comprehensive hydraulic analysis across all fluid systems on the same site.

Licensing and Download

All four AFT tools are available as commercial licenses in single-user and floating network configurations. Optional modules — ANS, GSC, XTS for Fathom and Arrow; SSL and PFA for Impulse; PFA for xStream — are available separately or in combined packages. For licensing inquiries and download access for any AFT product, contact our team via Telegram:

💬 Need a license or have questions? → Message us on Telegram — free consultation, usually reply within a few hours.

Frequently Asked Questions

What is the difference between AFT Fathom and AFT Arrow?

Fathom is built for liquid systems and low-velocity gas applications where density changes are negligible — it uses incompressible flow equations. Arrow is built for compressible gas and steam systems where density, temperature, and velocity change significantly along the flow path and sonic choking is a real concern — it uses a gas equation of state. If your system carries water, oil, or process liquids, use Fathom. If it carries natural gas, steam, compressed air, or process gases at significant velocity, use Arrow.

What is the difference between AFT Impulse and AFT xStream?

Both are MOC-based transient solvers, but they handle different fluid phases. Impulse analyzes pressure surges and water hammer in liquid systems — pump trips, valve slams, column separation, and cavitation. xStream analyzes compressible transients in gas and steam systems — pressure wave propagation, shocks, sonic choking, ESD sequences, and blowdowns. Choose based on whether your working fluid is liquid or gas.

Can a Fathom model be used directly in Impulse?

Yes. Because Fathom and Impulse share the same codebase and file format, any Fathom model can be opened directly in Impulse without modification. This makes the transition from steady-state design to water hammer transient analysis seamless — the steady-state Fathom results become the initialization condition for the Impulse transient run.

Which AFT tools are needed for a power plant project?

Power plants typically require multiple tools: Arrow for steady-state steam header design and fuel gas distribution, xStream for steam transient analysis during turbine trips and ESD sequences, Fathom for cooling water and boiler feedwater system design, and Impulse for water hammer analysis in those same liquid systems. The combination depends on the specific analysis scope of each project phase.

Are the optional modules available separately?

Yes. Each product’s base license covers the core simulation capability and is sufficient for most standard engineering tasks. Optional modules — ANS for automated sizing, GSC for goal seek and control, XTS for extended time simulation in Arrow and Fathom, SSL for slurry water hammer in Impulse, and PFA for pulsation frequency analysis in Impulse and xStream — are available separately or in combined packages. Contact us for guidance on the right combination for your specific application.

Do all four AFT tools support Excel integration and report export?

Yes. All four tools support Excel import and export for model data and results, configurable reports for design reviews and project deliverables, and color-mapped network result visualization. Impulse additionally exports transient force time histories to pipe stress analysis software. Arrow and Fathom support piping layout import from PCF, CAESAR II Neutral, EPANET, and GIS shapefiles.