title: Process Equipment Documentation description: Source-safe navigation and API ownership for process equipment in NeqSim. —

Use this index to choose an equipment-specific guide. For an executable, end-to-end flowsheet, start with the process-package quick start; it is compiled and run by the documentation regression suite.

The complete source-backed equipment catalog lists all 234 concrete ProcessEquipmentInterface implementations on the current source tree. Its generated inventory is checked in CI, so a newly added equipment class cannot remain absent from this documentation.

Equipment Categories

Flow Equipment

Equipment File Description
Streams streams.md Material and energy streams
Mixers & Splitters mixers_splitters.md Stream mixing and splitting
Manifolds manifolds.md Multi-inlet routing and production manifolds

Separation Equipment

Equipment File Description
Separators separators.md 2-phase and 3-phase separators, scrubbers
Separator Entrainment separator-entrainment-modeling.md Droplet distributions, internals, grade efficiency, and performance calculation
Distillation distillation.md Distillation columns
Absorbers absorbers.md Absorption/stripping columns
Adsorbers adsorbers.md Simplified adsorption equipment
Adsorption Beds adsorption_bed.md Dynamic beds, breakthrough, mercury removal, and PSA
Membranes membranes.md Membrane separation units
Filters filters.md Particulate and charcoal filters
Water Treatment water_treatment.md Hydrocyclones, flotation, produced-water treatment, and compliance
Black-Oil Separator black_oil_separator.md Pressure-temperature separation of SystemBlackOil fluids
Solid Handling solid_handling.md Feedstock preparation, dewatering, filtration, drying, and crystallization

Heat Transfer Equipment

Equipment File Description
Heat Exchangers heat_exchangers.md Heaters, coolers, condensers, reboilers
Multi-Stream Heat Exchangers multistream_heat_exchanger.md Composite curves, pinch constraints, and multi-stream matching
LNG Heat Exchanger LNGHeatExchanger.md Brazed-aluminium exchanger model for cryogenic service
Heat Integration heat_integration.md Heat streams and pinch analysis
Water Cooler and Reboiler water_cooler_reboiler.md Cooling-water and reboiler utilities

Rotating Equipment

Equipment File Description
Compressors compressors.md Gas compression, mechanical losses, seal gas
Compressor Curves compressor_curves.md Performance maps, correction, interpolation, and envelopes
Compressor Shaft compressor_shaft.md Multiple compressor bodies on a common-speed shaft
Compressor Anti-Surge Control compressor_antisurge_control.md Dynamic anti-surge recycle, speed/load control, and coordinated pressure-speed-recycle control philosophy
Pumps pumps.md Liquid pumping
Expanders expanders.md Power recovery, turboexpanders

Flow Control

Equipment File Description
Valves valves.md Throttling valves, chokes, safety valves
Control Valves control_valves.md Specialized pressure and level control valves

Reactors

Equipment File Description
Reactors (Overview) reactors.md All reactor types: PFR, CSTR, Gibbs, stoichiometric, ammonia, sulfur, bio-processing
Iron-Sulfide Wall Source iron_sulfide_wall_source.md Stateful FeS/FeCO3 scale, oxygen ingress, S8 generation, and compressor deposition coupling
Plug Flow Reactor plug_flow_reactor.md Kinetic PFR with power-law/LHHW/reversible kinetics, catalyst bed, Ergun ΔP, energy modes
Electrolyzers electrolyzers.md Water and CO₂ electrolysis

Ejectors

Equipment File Description
Ejectors ejectors.md Steam and gas ejectors

Safety Equipment

Equipment File Description
Flares flares.md Flare systems and combustion
Vessel Depressurization vessel_depressurization.md Blowdown, filling, fire exposure, and transient vessel inventory

Well/Reservoir

Equipment File Description
Wells wells.md Production wells, chokes
Reservoirs reservoirs.md Material balance reservoir modeling
Production Well Networks production_well_networks.md Coupled wells, flowlines, and network constraints
Well Allocation well_allocation.md Production allocation across wells
Subsea Systems subsea_systems.md Subsea wells and flowlines

Subsea Equipment

Equipment File Description
Subsea Equipment Overview subsea_equipment.md Complete SURF and subsea equipment selection
Subsea Trees subsea_trees.md Christmas trees, valve control
Subsea Manifolds subsea_manifolds.md Multi-slot production manifolds
Manifold Design manifold_design.md Mechanical design for topside, onshore, and subsea manifolds
Subsea Boosters subsea_boosters.md Multiphase pumps, compressors
Umbilicals umbilicals.md Hydraulic, chemical, electrical supply

Pipeline/Network

Equipment File Description
Pipelines pipelines.md Pipe flow, pressure drop
Pipeline Simulation pipeline_simulation.md Model selection, configuration, and execution
Multiphase Correlations multiphase_flow_correlations.md Pressure-drop, holdup, and flow-regime correlations
Risers pipelines.md#risers SCR, TTR, Flexible, Lazy-Wave risers
Networks networks.md Pipeline network modeling
Looped Networks looped_networks.md Hardy Cross solver for loops
Gas Network Operations ../gas_network_operations.md Coupled gas quality, optimization, and linepack
Oil Network Operations ../oil_network_operations.md Oil pumps, terminal tanks, parcels, and cargo schedules

Flow Measurement

Equipment File Description
Differential Pressure differential_pressure.md Orifice plates, flow measurement
Measurement Devices measurement_devices.md Flow, pressure, composition, and condition measurements

Storage

Equipment File Description
Tanks tanks.md Storage tanks, LNG boil-off
LNG Cargo Ageing ../lng-ageing.md Stratification, boil-off gas, rollover, voyage, and cargo-quality evolution

Power Generation

Equipment File Description
Power Equipment power_generation.md Gas turbines, fuel cells, renewables
Battery Storage battery_storage.md Energy storage systems
Energy Conversion energy_conversion.md Motors, generators, converters, thermal utilities, and energy-network solvers

Utility Equipment

Equipment File Description
Utility Index util/ Complete utility-equipment navigation
Adjusters util/adjusters.md Variable adjustment to meet specs
Recycles util/recycles.md Recycle stream handling
Calculators util/calculators.md Custom calculations and setters
Fuel Gas System util/fuel_gas_system.md Fuel-gas supply and balancing
Produced-Water Degassing util/produced_water_degassing.md Degassing-system utility model
Saturators util/saturators.md Water and component saturation utilities
Stream Fitters util/stream_fitters.md GOR, MPFM, and production-rate fitting
Utility Air System util/utility_air_system.md Instrument and plant-air utility modeling

Reliability & Failure

Equipment File Description
Failure Modes failure_modes.md Equipment failure modeling for risk analysis

Complete Source Inventory

Catalog Coverage Description
Complete equipment catalog 234 concrete classes in 33 source packages Generated from the Java inheritance tree and checked against source in CI

API Ownership

All process equipment implements ProcessEquipmentInterface, normally through ProcessEquipmentBaseClass. That common contract covers lifecycle, reporting, validation, mechanical design, capacity, fluid access, and common operating properties. It does not give every unit a single material inlet and outlet.

API owner Use it for Representative equipment
ProcessEquipmentInterface Common execution, reporting, design, validation, capacity, and fluid access All process equipment
TwoPortInterface / TwoPortEquipment One material inlet and one material outlet Heater, cooler, compressor, pump, expander, throttling valve
Equipment-specific multiport API Multiple feeds, products, or stages Separator, mixer, splitter, distillation column, absorber
Utility equipment API Graph dependencies, targets, and convergence Recycle, adjuster, calculator

For example, TwoPortEquipment owns getInletStream() and getOutletStream(). Separator instead exposes gas and liquid product streams and can accept multiple feeds. A mixer, splitter, or staged column likewise needs its own guide; do not assume the two-port constructor or accessors.

Constructing and Running Equipment

There is no universal EquipmentType(name, inletStream) constructor or setParameter(value) method. Follow the selected guide and current Java source for that equipment’s:

  1. constructor and stream topology;
  2. specification methods and units;
  3. required thermodynamic or physical-property initialization;
  4. steady-state or transient execution boundary;
  5. equipment-specific results and validation.

Add streams and equipment to one ProcessSystem, retain typed references, run the process, and check conservation plus equipment constraints. The canonical process-package example demonstrates this sequence with a feed, throttling valve, separator, mass-balance assertion, topology diagnostics, and structured reports.

ProcessSystem.getUnit(name) returns the common equipment interface. Cast only after verifying the expected type, or retain the typed reference created while building the process.

Equipment Hierarchy

ProcessEquipmentInterface
    └── ProcessEquipmentBaseClass
        ├── TwoPortEquipment implements TwoPortInterface
        │   ├── Heater / Cooler
        │   ├── Compressor / Pump / Expander
        │   └── ThrottlingValve
        ├── Separator and ThreePhaseSeparator (multi-inlet, multi-outlet)
        ├── Mixer (multi-inlet)
        ├── Splitter (multi-outlet)
        └── DistillationColumn and absorbers (staged, equipment-specific ports)

The diagram shows API ownership, not every concrete subtype.