Use this guide for a compact, copy-paste pump calculation. The example uses a vendor-style head, efficiency, and required-net-positive-suction-head (NPSHr) map. For API 610 screening, mechanical design, response JSON, and detailed model ownership, continue with the comprehensive pump guide.

Calculation basis

Item	Basis in the example
Thermodynamic state	298.15 K and 5.0 bara
Liquid	Pure n-hexane with the classic mixing rule
Actual inlet flow	100.0 m3/hr
Vendor-map speed	1000 rpm
Head curve	metres of pumped liquid
Efficiency curve	percent
NPSHr curve	metres of pumped liquid
Reported shaft power	kW

The program is a screening example, not a vendor selection. Run it with assertions enabled (-ea); the assertions are part of the published engineering evidence.

Executable Java example

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import neqsim.process.equipment.pump.Pump;
import neqsim.process.equipment.stream.Stream;
import neqsim.thermo.system.SystemInterface;
import neqsim.thermo.system.SystemSrkEos;

public final class PumpUsageGuideExample {
  private static final Logger logger = LogManager.getLogger(PumpUsageGuideExample.class);

  private PumpUsageGuideExample() {}

  public static void main(String[] args) {
    SystemInterface fluid = new SystemSrkEos(298.15, 5.0);
    fluid.addComponent("n-hexane", 1.0);
    fluid.setMixingRule("classic");

    Stream feed = new Stream("pump feed", fluid);
    feed.setFlowRate(100.0, "m3/hr");
    feed.run();

    Pump pump = new Pump("P-100", feed);
    double[] speedRpm = new double[] {1000.0};
    double[][] flowM3PerHour = new double[][] 50.0;
    double[][] headM = new double[][] 120.0;
    double[][] efficiencyPercent = new double[][] 65.0;
    double[][] npshRequiredM = new double[][] 2.0;

    pump.getPumpChart().setCurves(
        new double[] {}, speedRpm, flowM3PerHour, headM, efficiencyPercent);
    pump.getPumpChart().setHeadUnit("meter");
    pump.getPumpChart().setNPSHCurve(npshRequiredM);
    pump.setSpeed(1000.0);
    pump.setCheckNPSH(true);
    pump.setNPSHMargin(1.15);
    pump.run();

    double actualFlowM3PerHour = feed.getFlowRate("m3/hr");
    double vendorHeadM =
        pump.getPumpChart().getHead(actualFlowM3PerHour, pump.getSpeed());
    double powerKw = pump.getPower("kW");
    double npshAvailableM = pump.getNPSHAvailable();
    double requiredNpshM = pump.getNPSHRequired();

    assert Math.abs(actualFlowM3PerHour - 100.0) < 1.0e-9 : "Unexpected inlet flow";
    assert Math.abs(vendorHeadM - 105.0) < 1.0e-9 : "Unexpected map head";
    assert Double.isFinite(powerKw) && powerKw > 0.0 : "Pump power must be positive";
    assert Double.isFinite(npshAvailableM) : "NPSHa calculation failed";
    assert Math.abs(requiredNpshM - 3.0) < 0.02 : "Unexpected map NPSHr";
    assert npshAvailableM > requiredNpshM : "NPSHa must exceed NPSHr";
    assert !pump.isCavitating() : "Configured NPSH margin is not satisfied";

    logger.info(
        "Pump result: flow={} m3/hr, head={} m, power={} kW, NPSHa={} m, NPSHr={} m",
        actualFlowM3PerHour,
        vendorHeadM,
        powerKw,
        npshAvailableM,
        requiredNpshM);
  }
}

What the example verifies

• setCurves(...) activates the pump map at the supplied speed, flow, head, and efficiency points. All curve arrays must use the same point ordering.
• setHeadUnit("meter") declares the head-curve basis. Do not pass a pressure value into this curve.
• setNPSHCurve(...) supplies NPSHr from vendor data. At 100 m3/hr and 1000 rpm, the example interpolates exactly 3.0 m.
• getNPSHAvailable() estimates NPSHa from absolute suction pressure, calculated vapor pressure, liquid density, and zero velocity-head contribution. Elevation is not added inside this method; represent upstream pressure losses and static head in the suction system before the pump inlet.
• setNPSHMargin(1.15) makes isCavitating() compare NPSHa with 1.15 times NPSHr. A failed or non-finite NPSH calculation is treated as cavitation risk when checking is enabled.

Common operating modes

Objective	Configuration	Boundary
Specify discharge pressure	setOutletPressure(value, "bara")	Uses absolute bara; specify efficiency separately when required
Use vendor curves	getPumpChart().setCurves(...) and setSpeed(rpm)	Curve range, interpolation, fluid correction, and speed range require review
Specify outlet temperature	setOutletTemperature(value, "C")	A calculation mode, not a vendor-performance guarantee
Monitor cavitation screening	setCheckNPSH(true) and setNPSHMargin(factor)	Requires credible suction state and NPSHr evidence

Do not combine an outlet-pressure target with a vendor curve without first deciding which quantity owns the operating point. Retain typed Pump and Stream references so the result can be embedded in a larger ProcessSystem.

Troubleshooting

Observation	Check first
Non-finite NPSHa	Inlet phase, bubble-point calculation, absolute pressure, and initialized density
Unexpected head	Head unit, actual-flow unit, speed, curve ordering, and extrapolation outside vendor data
Unexpected power	Liquid density, efficiency curve, head basis, and whether the pump is using a map or a specified target
Cavitation warning	Suction pressure and temperature, upstream losses, static head, NPSHr data, and the selected margin
Result changes after composition update	Re-run the inlet stream and pump after changing composition, temperature, pressure, or flow

Engineering limits

This example checks software execution and basic physical consistency. It does not qualify a pump, suction vessel, piping system, driver, seal system, minimum-flow recycle, transient startup, or protection function. Use approved vendor curves over their documented speed and flow ranges, model the full suction system, evaluate maximum and minimum operating cases, and obtain accountable mechanical, process, electrical, and safety review before design use.