Pipelines and Pipes

Documentation for pipeline equipment in NeqSim.

📘 Comprehensive Documentation Available

For detailed documentation on all pipeline types, the PipeLineInterface, flow regime detection, heat transfer, profile methods, and complete examples, see:

• Pipeline Simulation Guide - Complete simulation documentation
• Pipeline Mechanical Design - Wall thickness, stress analysis, cost estimation
• Topside Piping Design - Platform piping with velocity, support spacing, vibration (AIV/FIV)
• Riser Mechanical Design - Riser design with catenary, VIV, fatigue
• Pipeline Mechanical Design Math - Mathematical formulas reference

Table of Contents

• Overview
• Pipe Segment
• Pipeline
• Topside Piping
• Risers
• Pressure Drop
• Heat Transfer
• Examples

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Overview

Location: neqsim.process.equipment.pipeline

Classes: | Class | Description | |——-|————-| | PipeBeggsAndBrills | Beggs-Brill correlation | | AdiabaticPipe | Adiabatic pipe segment | | OnePhasePipe | Single-phase pipe | | TwoPhasePipeLine | Two-phase pipeline | | TopsidePiping | Topside/platform piping with service types and mechanical design | | Riser | Subsea risers (SCR, TTR, Flexible, Lazy-Wave) |

For detailed pipe flow modeling, see also Fluid Mechanics.

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Pipe Segment

Basic Usage

import neqsim.process.equipment.pipeline.PipeBeggsAndBrills;

PipeBeggsAndBrills pipe = new PipeBeggsAndBrills("Pipe", inletStream);
pipe.setLength(1000.0, "m");
pipe.setDiameter(0.3, "m");
pipe.setAngle(0.0);  // Horizontal
pipe.run();

double pressureDrop = pipe.getPressureDrop("bara");
Stream outlet = pipe.getOutletStream();

Geometry

// Length
pipe.setLength(5000.0, "m");

// Inner diameter
pipe.setDiameter(0.254, "m");  // 10 inch
pipe.setInnerDiameter(0.254, "m");

// Wall roughness
pipe.setRoughness(0.0001, "m");

// Elevation change
pipe.setElevationChange(100.0, "m");  // 100m rise
pipe.setAngle(5.7);  // degrees from horizontal

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Pipeline

For longer pipelines with multiple segments.

Basic Usage

import neqsim.process.equipment.pipeline.TwoPhasePipeLine;

TwoPhasePipeLine pipeline = new TwoPhasePipeLine("Export Pipeline", inletStream);
pipeline.setLength(50000.0, "m");
pipeline.setDiameter(0.4, "m");
pipeline.setNumberOfNodes(100);
pipeline.run();

// Get profile
double[] pressure = pipeline.getPressureProfile();
double[] temperature = pipeline.getTemperatureProfile();
double[] holdup = pipeline.getLiquidHoldupProfile();

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Topside Piping

The TopsidePiping class provides specialized modeling for offshore platform and onshore facility piping with service type configuration and comprehensive mechanical design.

📘 Complete Documentation: Topside Piping Design

Service Types

Type	Description	Velocity Factor
PROCESS_GAS	Hydrocarbon gas	1.0
PROCESS_LIQUID	Hydrocarbon liquid	1.0
MULTIPHASE	Two-phase flow	0.8
STEAM	Steam service	1.2
FLARE	Flare headers	1.5
FUEL_GAS	Fuel gas system	0.9
COOLING_WATER	Cooling water	1.0
CHEMICAL_INJECTION	Chemical injection	0.8

Factory Methods

import neqsim.process.equipment.pipeline.TopsidePiping;

// Gas process header
TopsidePiping gasHeader = TopsidePiping.createProcessGas("Gas Header", feed);
gasHeader.setLength(50.0);
gasHeader.setDiameter(0.2032);  // 8 inch

// Flare header
TopsidePiping flareHeader = TopsidePiping.createFlareHeader("HP Flare", feed);

// Steam line
TopsidePiping steamLine = TopsidePiping.createSteamLine("HP Steam", feed);

// Cooling water
TopsidePiping cwLine = TopsidePiping.createCoolingWater("CW Supply", feed);

Configuration

TopsidePiping pipe = new TopsidePiping("Process Gas Header", feed);
pipe.setServiceType(TopsidePiping.ServiceType.PROCESS_GAS);
pipe.setPipeSchedule(TopsidePiping.PipeSchedule.SCH_40);
pipe.setLength(50.0);
pipe.setDiameter(0.2032);              // 8 inch ID
pipe.setElevation(0.0);

// Set operating envelope
pipe.setOperatingEnvelope(5.0, 80.0,   // Min/max pressure (bara)
                          -10.0, 60.0); // Min/max temperature (°C)

// Set fittings
pipe.setFittings(4, 2, 1, 2);  // 4 elbows, 2 tees, 1 reducer, 2 valves

// Set insulation
pipe.setInsulation(TopsidePiping.InsulationType.MINERAL_WOOL, 0.05);  // 50mm

// Set flange rating
pipe.setFlangeRating(300);  // ASME B16.5 Class 300

pipe.run();

Mechanical Design

// Get mechanical design
TopsidePipingMechanicalDesign design = pipe.getTopsideMechanicalDesign();
design.setMaxOperationPressure(80.0);
design.setMaterialGrade("A106-B");
design.setDesignStandardCode("ASME-B31.3");
design.setCompanySpecificDesignStandards("Equinor");

// Run design calculations
design.readDesignSpecifications();
design.calcDesign();

// Get results
TopsidePipingMechanicalDesignCalculator calc = design.getTopsideCalculator();
System.out.println("Support spacing: " + calc.getSupportSpacing() + " m");
System.out.println("Velocity OK: " + calc.isVelocityCheckPassed());
System.out.println("Vibration OK: " + calc.isVibrationCheckPassed());
System.out.println("Stress OK: " + calc.isStressCheckPassed());

// Export JSON report
String json = design.toJson();

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Risers

The Riser class provides specialized modeling for subsea risers with support for various riser configurations and dedicated mechanical design calculations.

Riser Types

Type	Description	Key Features
STEEL_CATENARY_RISER (SCR)	Free-hanging catenary from FPSO	Touchdown point stress, catenary mechanics
TOP_TENSIONED_RISER (TTR)	Tensioned from platform	Stroke requirements, tension variation
FLEXIBLE_RISER	Unbonded flexible pipe	Bend radius limits, fatigue
LAZY_WAVE	SCR with buoyancy modules	Reduces touchdown stress
STEEP_WAVE	Steep wave configuration	Compact footprint
HYBRID_RISER	Jumper + tower riser	Deep water applications
FREE_STANDING	Tower riser	Ultra-deep water
VERTICAL	Vertical tensioned	TLP applications

Factory Methods

import neqsim.process.equipment.pipeline.Riser;

// Steel Catenary Riser
Riser scr = Riser.createSCR("Production SCR", inletStream, 800.0);  // 800m water depth

// Top Tensioned Riser
Riser ttr = Riser.createTTR("Export TTR", inletStream, 500.0);

// Lazy-Wave Riser
Riser lazyWave = Riser.createLazyWave("Gas Export", inletStream, 1200.0, 400.0);  // buoyancy at 400m

// Flexible Riser
Riser flexible = Riser.createFlexible("Water Injection", inletStream, 300.0);

// Hybrid Riser
Riser hybrid = Riser.createHybrid("Deepwater Export", inletStream, 2000.0);

Riser Configuration

Riser riser = new Riser("Production Riser", inletStream);
riser.setRiserType(Riser.RiserType.STEEL_CATENARY_RISER);
riser.setWaterDepth(800.0);            // Water depth in meters
riser.setTopAngle(12.0);               // Angle from vertical at top (degrees)
riser.setDepartureAngle(18.0);         // Angle from horizontal at seabed
riser.setDiameter(0.254);              // Inner diameter in meters (10 inch)

// Environmental conditions
riser.setCurrentVelocity(0.8);         // Mid-depth current (m/s)
riser.setSeabedCurrentVelocity(0.3);   // Seabed current (m/s)
riser.setSignificantWaveHeight(4.0);   // Hs in meters
riser.setPeakWavePeriod(12.0);         // Tp in seconds
riser.setPlatformHeaveAmplitude(3.0);  // Heave motion (m)

// TTR specific
riser.setAppliedTopTension(2000.0);    // Top tension in kN

// Lazy-wave specific
riser.setBuoyancyModuleDepth(400.0);   // Depth of buoyancy section
riser.setBuoyancyModuleLength(150.0);  // Length of buoyancy section

riser.run();

Riser Mechanical Design

The RiserMechanicalDesign class provides riser-specific mechanical design calculations per DNV-OS-F201, DNV-RP-F204, and API RP 2RD.

Riser riser = Riser.createSCR("Export Riser", inletStream, 1000.0);
riser.setDiameter(0.3048);  // 12 inch
riser.setCurrentVelocity(0.6);
riser.setSignificantWaveHeight(3.5);
riser.run();

// Get mechanical design
RiserMechanicalDesign design = riser.getRiserMechanicalDesign();
design.setMaxOperationPressure(150.0);
design.setMaterialGrade("X65");
design.setDesignStandardCode("DNV-OS-F201");
design.setCompanySpecificDesignStandards("Equinor");

design.readDesignSpecifications();
design.calcDesign();

// Get riser-specific results
RiserMechanicalDesignCalculator calc = design.getRiserCalculator();

// Top tension (catenary/TTR)
double topTension = calc.getTopTension();         // kN
double minTension = calc.getMinTopTension();      // kN
double maxTension = calc.getMaxTopTension();      // kN

// Touchdown point analysis
double tdpStress = calc.getTouchdownPointStress();     // MPa
double tdpRadius = calc.getTouchdownCurvatureRadius(); // m
double tdpLength = calc.getTouchdownZoneLength();      // m

// VIV response
double vivFreq = calc.getVortexSheddingFrequency();   // Hz
double natFreq = calc.getNaturalFrequency();          // Hz
double vivAmp = calc.getVIVAmplitude();               // A/D ratio
boolean lockIn = calc.isVIVLockIn();

// Dynamic response
double waveStress = calc.getWaveInducedStress();      // MPa
double heaveStress = calc.getHeaveInducedStress();    // MPa
double strokeReq = calc.getStrokeRequirement();       // m (TTR)

// Fatigue analysis
double fatigueLife = calc.getRiserFatigueLife();      // years
double vivDamage = calc.getVIVFatigueDamage();        // per year

// Check design
boolean acceptable = design.isDesignAcceptable();

Riser Design Standards

Parameters are loaded from the NeqSim design database:

Standard	Parameters
DNV-OS-F201	Usage factor, safety class factors, DAF, max utilization
DNV-RP-F204	Fatigue design factor, S-N curve parameters, SCF
DNV-RP-C203	S-N curve parameters (seawater, air)
DNV-RP-C205	Strouhal number, drag/lift/added mass coefficients
API RP 2RD	Design factor, dynamic load factor
API RP 17B	Min bend radius, max axial strain (flexible)

JSON Export

// Full design report
String json = design.toJson();

// Calculator results
String calcJson = calc.toJson();

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Pressure Drop

Friction Factor Correlations

Method	Application
Beggs-Brill	Two-phase flow
Moody	Single-phase turbulent
Colebrook	Single-phase implicit

Beggs-Brill Correlation

PipeBeggsAndBrills pipe = new PipeBeggsAndBrills("Pipe", stream);
pipe.setLength(1000.0, "m");
pipe.setDiameter(0.3, "m");
pipe.run();

// Flow regime
String regime = pipe.getFlowRegime();  // Segregated, Intermittent, Distributed

// Liquid holdup
double holdup = pipe.getLiquidHoldup();

Pressure Drop Components

\[\Delta P_{total} = \Delta P_{friction} + \Delta P_{elevation} + \Delta P_{acceleration}\]

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Heat Transfer

Adiabatic Pipe

import neqsim.process.equipment.pipeline.AdiabaticPipe;

AdiabaticPipe pipe = new AdiabaticPipe("Adiabatic Pipe", stream);
pipe.setLength(500.0, "m");
pipe.setDiameter(0.2, "m");
pipe.run();

// Temperature remains constant (no heat loss)
double Tin = pipe.getInletStream().getTemperature("C");
double Tout = pipe.getOutletStream().getTemperature("C");

Pipe with Heat Transfer

PipeBeggsAndBrills pipe = new PipeBeggsAndBrills("Pipe", stream);
pipe.setLength(1000.0, "m");
pipe.setDiameter(0.3, "m");

// Heat transfer coefficient
pipe.setOverallHeatTransferCoefficient(25.0, "W/m2K");

// Ambient temperature
pipe.setAmbientTemperature(5.0, "C");

pipe.run();

double heatLoss = pipe.getHeatLoss("kW");

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Examples

Example 1: Simple Pipe Segment

import neqsim.thermo.system.SystemSrkEos;
import neqsim.process.equipment.stream.Stream;
import neqsim.process.equipment.pipeline.PipeBeggsAndBrills;

// Natural gas
SystemSrkEos gas = new SystemSrkEos(303.15, 80.0);
gas.addComponent("methane", 0.90);
gas.addComponent("ethane", 0.07);
gas.addComponent("propane", 0.03);
gas.setMixingRule("classic");

Stream inlet = new Stream("Inlet", gas);
inlet.setFlowRate(1000000.0, "Sm3/day");
inlet.run();

// Pipe
PipeBeggsAndBrills pipe = new PipeBeggsAndBrills("Pipe", inlet);
pipe.setLength(5000.0, "m");
pipe.setDiameter(0.254, "m");  // 10 inch
pipe.setRoughness(0.00005, "m");
pipe.run();

System.out.println("Inlet P: " + inlet.getPressure("bara") + " bara");
System.out.println("Outlet P: " + pipe.getOutletStream().getPressure("bara") + " bara");
System.out.println("ΔP: " + pipe.getPressureDrop("bara") + " bara");
System.out.println("Velocity: " + pipe.getVelocity("m/s") + " m/s");

Example 2: Two-Phase Pipeline

// Wellstream (gas + condensate)
SystemSrkEos wellstream = new SystemSrkEos(350.0, 100.0);
wellstream.addComponent("methane", 0.70);
wellstream.addComponent("ethane", 0.10);
wellstream.addComponent("propane", 0.08);
wellstream.addComponent("n-pentane", 0.05);
wellstream.addComponent("n-heptane", 0.05);
wellstream.addComponent("n-decane", 0.02);
wellstream.setMixingRule("classic");

Stream inlet = new Stream("Wellstream", wellstream);
inlet.setFlowRate(50000.0, "kg/hr");
inlet.run();

// Two-phase pipeline
TwoPhasePipeLine pipeline = new TwoPhasePipeLine("Flowline", inlet);
pipeline.setLength(10000.0, "m");
pipeline.setDiameter(0.2, "m");
pipeline.setNumberOfNodes(50);
pipeline.run();

System.out.println("Inlet: " + inlet.getPressure("bara") + " bara, " + 
                   inlet.getTemperature("C") + " °C");
System.out.println("Outlet: " + pipeline.getOutletStream().getPressure("bara") + " bara, " +
                   pipeline.getOutletStream().getTemperature("C") + " °C");

Example 3: Subsea Pipeline with Heat Loss

// Subsea conditions
SystemSrkEos gas = new SystemSrkEos(350.0, 150.0);
gas.addComponent("methane", 0.92);
gas.addComponent("ethane", 0.05);
gas.addComponent("CO2", 0.02);
gas.addComponent("water", 0.01);
gas.setMixingRule("classic");

Stream inlet = new Stream("Wellhead", gas);
inlet.setFlowRate(5000000.0, "Sm3/day");
inlet.run();

// Subsea pipeline
PipeBeggsAndBrills pipeline = new PipeBeggsAndBrills("Subsea", inlet);
pipeline.setLength(50000.0, "m");
pipeline.setDiameter(0.4, "m");
pipeline.setOverallHeatTransferCoefficient(15.0, "W/m2K");
pipeline.setAmbientTemperature(4.0, "C");  // Seabed temperature
pipeline.run();

System.out.println("Outlet temperature: " + pipeline.getOutletStream().getTemperature("C") + " °C");
System.out.println("Heat loss: " + pipeline.getHeatLoss("MW") + " MW");

// Check hydrate temperature
double hdtTemp = pipeline.getOutletStream().getFluid().getHydrateTemperature();
System.out.println("Hydrate temperature: " + (hdtTemp - 273.15) + " °C");

Example 4: Steel Catenary Riser

import neqsim.process.equipment.pipeline.Riser;
import neqsim.process.mechanicaldesign.pipeline.RiserMechanicalDesign;

// Production stream
Stream production = new Stream("Production", wellFluid);
production.setFlowRate(10000.0, "kg/hr");
production.run();

// Steel Catenary Riser (800m water depth)
Riser riser = Riser.createSCR("Production Riser", production, 800.0);
riser.setDiameter(0.254);              // 10 inch
riser.setTopAngle(12.0);               // 12 degrees from vertical
riser.setCurrentVelocity(0.6);         // 0.6 m/s current
riser.setSignificantWaveHeight(3.5);   // Hs = 3.5m
riser.run();

System.out.println("Bottom P: " + production.getPressure("bara") + " bara");
System.out.println("Top P: " + riser.getOutletStream().getPressure("bara") + " bara");
System.out.println("Flow regime: " + riser.getFlowRegime());
System.out.println("Riser length: " + riser.getLength() + " m");

// Mechanical design
RiserMechanicalDesign design = riser.getRiserMechanicalDesign();
design.setMaxOperationPressure(100.0);
design.setMaterialGrade("X65");
design.readDesignSpecifications();
design.calcDesign();

System.out.println("Top tension: " + design.getRiserCalculator().getTopTension() + " kN");
System.out.println("Fatigue life: " + design.getRiserCalculator().getRiserFatigueLife() + " years");
System.out.println("VIV lock-in: " + design.getRiserCalculator().isVIVLockIn());

Example 5: Top Tensioned Riser

// TTR for TLP
Riser ttr = Riser.createTTR("Export TTR", production, 500.0);
ttr.setDiameter(0.3048);  // 12 inch
ttr.setAppliedTopTension(2500.0);  // 2500 kN applied tension
ttr.setTensionVariationFactor(0.15);  // 15% variation from heave
ttr.setPlatformHeaveAmplitude(2.5);
ttr.run();

RiserMechanicalDesign ttrDesign = ttr.getRiserMechanicalDesign();
ttrDesign.setMaxOperationPressure(200.0);
ttrDesign.setMaterialGrade("X65");
ttrDesign.calcDesign();

System.out.println("TTR tension: " + ttrDesign.getRiserCalculator().getTopTension() + " kN");
System.out.println("Stroke requirement: " + ttrDesign.getRiserCalculator().getStrokeRequirement() + " m");

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Related Documentation

• Equipment Index - All equipment
• Fluid Mechanics - Detailed pipe flow
• Pipeline Mechanical Design - Wall thickness, stress, costs
• Riser Mechanical Design - Riser-specific design
• Valves - Flow control