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Impulse

Calculate pressure surge transients in liquid piping systems

Ensure pressure extremes stay within design limits and troubleshoot operational issues before they happen.

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Predict Pressure Surge

Calculate pressure surges and size equipment to safeguard your system.

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Scenario Manager

Track multiple “What-If“ operating cases within one file and compare multiple transient scenarios in seconds.

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Visual Reporting

Animate events and export clear graphs and data for quick insights.

Transient Surge Solver & Physics

Predict pressure surges, flows, and forces during water hammer events with an MOC-based transient solver.

  • Models cavitation and column separation.
  • Handles event- and time-driven operations (valve closures, pump trips/restarts, ESDs).
  • Accounts for wave speed and system elasticity.
  • Visualizes results with animations and pressure/flow/force plots.
Transient Surge Solver & Physics

Pump & Valve Transient Modeling

Capture real equipment behavior during trips, reversals, startups, and control actions.

  • Centrifugal and PD pump transients with pump inertia/driver torque and four-quadrant curves.
  • NPSH checks and check-valve dynamics to mitigate slam.
  • Time-dependent valve characteristics (Cv/K vs. time) and control-valve logic with rate limits.
  • Relief-valve modeling with opening profiles and setpoints.
Pump & Valve Transient Modeling

Surge Protection & System Devices

Evaluate and size surge-control equipment such as tanks, gas accumulators, and air/vacuum valves.to keep pressures within limits.
  • Design alerts to enforce allowable pressures and velocities.
  • Compare device sizing, setpoints, and locations across scenarios.
  • Optional modules for pulsation (API 674 checks) and slurry water hammer.
Surge Protection & System Devices

Workflow and Integration

Build, manage, and share models efficiently—and connect results to stress analysis.

  • Scenario Manager to track alternatives in one file.
  • Excel import/export for model data and results.
  • Import piping from CAESAR II® Neutral files, PCF files, and GIS shapefiles.
  • Export unbalanced forces to CAESAR II®, TRIFLEX®, ROHR2, and AutoPIPE.
Workflow and Integration

Visualization & Reporting

Clearly communicate transient behavior.
  • Animate pressure waves, flows, and levels; apply color maps on the model.
  • Create time-history graphs, max/min envelopes, and cross-plots.
  • Export videos, images, and configurable report packages.
Visualization & Reporting

Fluids & Property Libraries

Use verified, extensible databases for liquid transients.
  • Standard Fluids, NIST REFPROP, and ASME Steam Tables included; optional Chempak (~700 fluids with mixing).
  • Support for temperature-dependent properties and user-defined fluids.
  • Non-Newtonian options (e.g., Power Law, Bingham) for specialty applications.
Fluids & Property Libraries

Model Initialization & Operating Limits

Start from a consistent steady state and enforce allowable conditions.
  • Automatic steady-state initialization with reservoirs, control valves, and time-varying boundaries.
  • Elevation profiles and partially filled pipe ends where systems drain between runs.
  • Design alerts for pressure, velocity, NPSH, and other engineering limits.
Model Initialization & Operating Limits

Settling Slurry (SSL Module)

Analyze waterhammer in slurries where solids change wave speed, damping, and friction.
  • Model both settling and non-settling slurry transients.
  • Account for solids concentration effects on density, viscosity, and acoustic wave speed.
  • Apply slurry-specific friction correlations to estimate pressure loss and energy requirements.
  • Evaluate pump performance and NPSH under slurry conditions; assess derating needs.
  • Optimize pipe diameter and target velocities to reduce deposition or erosion risk.
Settling Slurry (SSL Module)

Pulsation Frequency Analysis (PFA Module)

Quantify positive-displacement pump pulsations and avoid acoustic resonance.
  • Build an acoustic model to calculate natural frequencies and pump-order forcing.
  • Check peak-to-peak pulsation against acceptance limits (e.g., API 674).
  • Size and place pulsation control devices (bottles, accumulators, volume chambers, orifices).
  • Identify resonance risks in header/branch configurations and verify mitigation across the operating range.
  • Use spectral plots and envelopes to compare alternatives and document compliance.
Pulsation Frequency Analysis (PFA Module)

Validation

Our software is the leading pipe-flow modeling tool to accurately model surge, validate modifications, and prevent outages.
Explore Customer Stories
Pump Elimination
Tata
5.5 MW saved
Data Center Surge
Data Center - Feature 6
3,000 Pipe System
Petrochemical Surge Mitigation
Petrochemical-3
Matched field data Validated Data
Desalination Surge Control
Procure
$175,000 Annual Saving

Questions?

We have answers! Here are some of the most common questions we hear from engineers and companies evaluating Impulse. Topics include cavitation and column separation, liquid transient modeling, pump transients, non-Newtonian fluids, partially filled pipes, operating limits, steady-state differences from Fathom, and fluid property databases.
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Does Impulse model cavitation and column separation?

Yes, Impulse models transient cavitation using the Discrete Vapor Cavity Model (DVCM) and Discrete Gas Cavity Model (DGCM).

Can Impulse simulate gas transients?

No, Impulse models transients in liquid systems only.

How are pump transients handled (trips, restarts, reverse flow)?

Pumps can be modeled with a prescribed speed profile or with speed calculated from pump inertia; positive displacement pump transients (periodic flow, startup, shutdown) are supported.

Can I model non-Newtonian fluids or pulp-and-paper systems?

Yes—Power Law and Bingham Plastic models are available, plus Duffy and Brecht & Heller methods for pulp-and-paper applications.

Can Impulse model partially filled pipes?

Yes, as of Impulse 11, pipe filling is now a valuable feature for engineers analyzing surge and bubbles in startup systems.

Can I set operating limits and use elevation profiles?

Yes—define min/max operating pressures as design alerts (with cross-plots to pressure profiles) and assign elevation profiles to individual pipes; control valves are supported.

How does Impulse’s steady-state differ from Fathom?

Impulse uses the same steady-state method but only for waterhammer initialization. It does not analyze heat transfer, has no static-element junctions (modeled via losses or general components), and has no pump/system curve graphing. Because they share the same code-base and interface, you can easily transition your Fathom model to Impulse simply by changing the url.

What fluid property databases are included?

Standard Fluids and NIST REFPROP are included; the optional Chempak add-on provides up to ~700 fluids with mixing and an Excel add-in.
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Learn more about how Impulse can improve your designs and results.

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