ManifoldMechanicalDesignCalculator provides deterministic screening calculations for topside, onshore, and subsea manifold concepts. Use it to organize preliminary geometry, pressure, temperature, flow, material, support, reinforcement, and weight evidence. It is not a detailed piping design package, a code-compliance certificate, or a substitute for discipline review.

Use the current NeqSim JavaDoc when checking the public API alongside the source contracts described below.

The calculator is the clearest public boundary when inputs and units must be explicit. The equipment-owned ManifoldMechanicalDesign bridge is described separately because its current pressure handoff requires additional verification.

Input and result contract

The calculator does not attach unit strings to setters. Convert every input before calling it.

Quantity Setter or result Required unit or basis
Design pressure setDesignPressure(double) MPa
Design temperature setDesignTemperature(double) °C
Header and branch diameters setHeaderOuterDiameter, setBranchOuterDiameter m, outside diameter
Header and branch wall setHeaderWallThickness, setBranchWallThickness m
Corrosion allowance setCorrosionAllowance(double) m
Mass flow setMassFlowRate(double) kg/s, total manifold flow
Mixture density setMixtureDensity(double) kg/m³
Liquid fraction setLiquidFraction(double) volume fraction from 0 to 1
Header length and support spacing setters and getters m
Calculated weight getTotalDryWeight() kg

ManifoldLocation accepts TOPSIDE, ONSHORE, or SUBSEA. ManifoldType accepts PRODUCTION, INJECTION, TEST, PIGGING, or DISTRIBUTION.

Complete screening example

This Java 8 program is extracted, compiled, and executed from this page during the repository test suite. The values are illustrative screening inputs, not a project design basis.

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import neqsim.process.mechanicaldesign.manifold.ManifoldMechanicalDesignCalculator;
import neqsim.process.mechanicaldesign.manifold.ManifoldMechanicalDesignCalculator.ManifoldLocation;
import neqsim.process.mechanicaldesign.manifold.ManifoldMechanicalDesignCalculator.ManifoldType;

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

  private ManifoldMechanicalDesignScreeningExample() {}

  public static void main(String[] args) {
    ManifoldMechanicalDesignCalculator calculator =
        new ManifoldMechanicalDesignCalculator();
    calculator.setLocation(ManifoldLocation.TOPSIDE);
    calculator.setManifoldType(ManifoldType.PRODUCTION);
    calculator.setMaterialGrade("A106-B");
    calculator.setDesignPressure(5.5); // MPa
    calculator.setDesignTemperature(25.0); // °C
    calculator.setHeaderOuterDiameter(0.3048); // m
    calculator.setHeaderWallThickness(0.0200); // m
    calculator.setBranchOuterDiameter(0.1524); // m
    calculator.setBranchWallThickness(0.0150); // m
    calculator.setCorrosionAllowance(0.0030); // m
    calculator.setHeaderLength(5.0); // m
    calculator.setNumberOfInlets(1);
    calculator.setNumberOfOutlets(2);
    calculator.setNumberOfValves(4);
    calculator.setMassFlowRate(0.25); // kg/s
    calculator.setMixtureDensity(35.0); // kg/m3
    calculator.setLiquidFraction(0.0); // liquid volume fraction

    boolean screeningPass = calculator.performDesignVerification();
    String json = calculator.toJson();

    assert screeningPass;
    assert calculator.isWallThicknessCheckPassed();
    assert calculator.isVelocityCheckPassed();
    assert calculator.isReinforcementCheckPassed();
    assert calculator.getMinHeaderWallThickness() > 0.0;
    assert calculator.getMinHeaderWallThickness()
        < calculator.getHeaderWallThickness();
    assert calculator.getMinBranchWallThickness() > 0.0;
    assert calculator.getHeaderVelocity() > 0.0;
    assert calculator.getBranchVelocity() > 0.0;
    assert calculator.getErosionalVelocity() > calculator.getHeaderVelocity();
    assert calculator.getSupportSpacing() > 0.0;
    assert calculator.getNumberOfSupports() >= 2;
    assert calculator.getTotalDryWeight() > 0.0;
    assert json.contains("wallThicknessAnalysis");
    assert json.contains("velocityAnalysis");
    assert json.contains("supportAnalysis");

    logger.info(
        "Screening pass {}; minimum header wall {} mm; header velocity {} m/s; dry weight {} kg",
        screeningPass,
        calculator.getMinHeaderWallThickness() * 1000.0,
        calculator.getHeaderVelocity(),
        calculator.getTotalDryWeight());
  }
}

The example checks calculation integrity and internally consistent inputs. It does not establish that the assumed material, corrosion allowance, geometry, or limits are suitable for a project.

What the verification method checks

performDesignVerification() runs the current implementation in this order:

  1. minimum header and branch wall calculations;
  2. comparison of configured wall thicknesses with calculated minima;
  3. header and branch velocity screening;
  4. branch-reinforcement area screening;
  5. support-spacing and dry-weight estimates;
  6. submerged-weight estimation when the location is SUBSEA.

Read the individual flags with isWallThicknessCheckPassed(), isVelocityCheckPassed(), and isReinforcementCheckPassed(). The returned Boolean is the conjunction of those three checks. Support and weight are calculated but do not add independent pass/fail criteria.

The JSON report exposes configuration, geometry, design conditions, material properties, wall, velocity, reinforcement, weight, support, and the strings recorded in appliedStandards. Those strings identify calculation branches; they are not evidence that a complete standards review was performed.

Implemented equations

For TOPSIDE and ONSHORE, the implemented minimum-wall expression is:

\[t_m=\frac{PD}{2(SE+PY)}\] \[t_{\min}=\frac{t_m}{f_{\mathrm{tol}}}+c\]

Here, $P$ is in MPa, $D$ and $t$ are in metres, $S$ is in MPa, $E$ is joint efficiency, $Y$ is the implementation coefficient, $f_{\mathrm{tol}}$ is the fabrication-tolerance factor, and $c$ is corrosion allowance in metres.

For SUBSEA, the implemented pressure-containment expression is:

\[t_1=\frac{PD}{2f_y/(\gamma_M\gamma_{SC})}\]

The calculator also evaluates the screening erosional velocity as:

\[v_e=\frac{C}{\sqrt{\rho_m}}\]

These are descriptions of the current source calculations. They do not demonstrate compliance with a particular edition of ASME B31.3, DNV-ST-F101, API RP 14E, NORSOK L-002, or another project standard. The current subsea wall expression calculates seabed external pressure from water depth but does not use that value in a collapse or combined-pressure check.

Equipment bridge boundary

Manifold.initMechanicalDesign() creates a ManifoldMechanicalDesign. Its calcDesign() method copies configured geometry and stream-derived density, mass flow, and liquid fraction into the calculator before running the same screening verification.

Do not treat that bridge as a unit-safe design calculation on the current source. The inherited setMaxOperationPressure(double) contract stores bara, while the bridge multiplies that value by 1.1 and passes it directly to the calculator field whose contract is MPa. Use an explicitly converted calculator input, as in the executable example, until the bridge conversion is corrected and independently validated. The temperature handoff converts kelvin to degrees Celsius.

Data and standards boundary

ManifoldMechanicalDesignDataSource attempts to load selected company and standards parameters from TechnicalRequirements_Process, asme_standards, and dnv_iso_en_standards. Database failures are logged and calculator defaults remain in use. The JSON output does not establish the database row, document edition, material certificate, or project requirement that supplied a value.

Before engineering use, preserve and independently verify at least:

The dry-weight model uses simplified pipe, valve, reinforcement, and structure estimates. The submerged-weight model uses a simplified solid-volume fraction. Neither result is a lifting, transport, installation, or structural design.