FIND YOUR CONSULTANT
JOIN OUR COMMUNITY
FIND YOUR CONSULTANT
JOIN OUR COMMUNITY
Resources >

Oil & Gas Industry Acronyms >

LNG Value Chain Industry Acronyms

LNG Value Chain Industry Acronyms

Receive consulting resources in your inbox

This glossary explains the operational, technical, commercial, safety, regulatory, and performance acronyms most relevant to the Oil & Gas sector’s LNG activities. It helps executives, operators, engineers, and advisors navigate terminology used across the LNG Value Chain Practice, from liquefaction and shipping to regasification, contracting, and emissions management.

0–9 A B C D E F G H I J L M N O P Q R S T U V W X

0–9
33 CFR Part 127 Title 33 of the Code of Federal Regulations, Part 127:
United States requirements governing waterfront facilities that handle liquefied natural gas and other liquefied hazardous gases, including transfer operations, security, firefighting, and equipment.
49 CFR Part 193 Title 49 of the Code of Federal Regulations, Part 193:
United States federal safety standards covering the siting, design, construction, operation, maintenance, and security of liquefied natural gas facilities.
A
AACQ Adjusted Annual Contract Quantity:
The annual volume a buyer is obligated or entitled to take after applying contractual adjustments for matters such as outages, diversions, or prior-year entitlements.
AAV Ambient Air Vaporizer:
A heat exchanger that uses surrounding air to warm and regasify cryogenic liquid, reducing fuel consumption where climate and site conditions are suitable.
ACQ Annual Contract Quantity:
The quantity scheduled for purchase or delivery during a contract year under a long-term sale and purchase agreement.
ADP Annual Delivery Programme:
The agreed yearly schedule of cargo delivery windows, quantities, and destinations used to coordinate production, shipping, and terminal capacity.
AGA American Gas Association:
An industry organization whose measurement reports and standards support gas metering, compressibility calculations, and custody-transfer accuracy at receiving terminals.
AGR Acid Gas Removal:
Feed-gas treatment that removes carbon dioxide, hydrogen sulfide, and related contaminants before liquefaction to prevent freezing, corrosion, and off-specification product.
AGRU Acid Gas Removal Unit:
The process unit, commonly based on amine absorption, that performs acid-gas removal from feed gas.
AIS Automatic Identification System:
A maritime tracking system that transmits vessel identity, position, course, and speed for traffic management, voyage monitoring, and terminal planning.
ALARP As Low As Reasonably Practicable:
A risk-reduction principle requiring hazards to be mitigated until further reduction would be grossly disproportionate to the benefit achieved.
AP-C3MR Air Products Propane Pre-cooled Mixed Refrigerant:
A widely deployed liquefaction process using propane for precooling and a mixed refrigerant for final cooling and liquefaction.
AP-DMR Air Products Dual Mixed Refrigerant:
A liquefaction process using separate mixed-refrigerant cycles for precooling and liquefaction, offering flexibility for large plants and warmer climates.
AP-SMR Air Products Single Mixed Refrigerant:
A single-cycle liquefaction technology often applied to smaller trains, peak-shaving plants, and modular developments.
API 620 American Petroleum Institute Standard 620, Design and Construction of Large, Welded, Low-Pressure Storage Tanks:
A design and construction standard commonly referenced for low-pressure refrigerated storage tank components.
API 625 American Petroleum Institute Standard 625, Tank Systems for Refrigerated Liquefied Gas Storage:
A standard addressing complete refrigerated storage tank systems, including containment concepts, foundation interfaces, and system-level design requirements.
ATEX Atmosphères Explosibles:
The European regulatory framework for equipment and workplaces exposed to potentially explosive atmospheres, directly affecting hazardous-area classification and equipment selection.
B
BAHX Brazed Aluminum Heat Exchanger:
A compact exchanger providing multiple process streams and high heat-transfer efficiency for cryogenic liquefaction, subcooling, and feed-treatment services.
Bcf/d Billion Cubic Feet per Day:
A gas-flow unit used to express feed-gas demand, liquefaction capacity, and terminal sendout rates.
bcm Billion Cubic Metres:
A volume unit commonly used for international gas reserves, trade, storage, and market-demand comparisons.
bcma Billion Cubic Metres per Annum:
An annualized capacity unit used for liquefaction feed gas, regasification sendout, and market infrastructure.
B/L Bill of Lading:
The shipping document recording cargo quantity, apparent condition, loading details, and title or receipt information for a marine cargo.
BLEVE Boiling Liquid Expanding Vapor Explosion:
A hazardous pressure-vessel failure involving rapid depressurization of liquid above its atmospheric boiling point; it is considered in risk assessments for pressurized cryogenic systems.
BOG Boil-Off Gas:
Vapor generated as heat enters cryogenic cargo or storage tanks. It must be recovered, compressed, consumed as fuel, reliquefied, exported, or safely disposed of.
BOR Boil-Off Rate:
The percentage of stored cargo that vaporizes over a specified period, typically per day, and a key measure of tank and carrier thermal performance.
BTEX Benzene, Toluene, Ethylbenzene, and Xylenes:
Aromatic hydrocarbons monitored and removed from feed gas because they can freeze in cryogenic equipment and create environmental or occupational exposure concerns.
Btu British Thermal Unit:
A unit of energy widely used in gas pricing, heating-value specifications, and cargo valuation.
C
C3MR Propane Pre-cooled Mixed Refrigerant:
A liquefaction-cycle configuration in which a propane circuit precools feed gas and refrigerant before a mixed-refrigerant circuit completes liquefaction and subcooling.
CCS Carbon Capture and Storage:
The capture, transport, and permanent geological storage of carbon dioxide, used to reduce emissions from feed-gas treatment, fuel combustion, and other plant sources.
CCS Cargo Containment System:
The shipboard tank system, insulation, barriers, supports, and associated structures that safely contain cryogenic cargo during loading, transit, and unloading.
CCUS Carbon Capture, Utilization, and Storage:
An emissions-management approach that adds beneficial use of captured carbon dioxide to capture and permanent storage options.
CFR Cost and Freight:
An Incoterms delivery rule under which the seller pays freight to the named destination while marine cargo risk transfers when the goods are loaded aboard the vessel.
CI Carbon Intensity:
Greenhouse-gas emissions per unit of energy, cargo, or production, used to compare supply pathways and track decarbonization performance.
CIF Cost, Insurance and Freight:
An Incoterms delivery rule requiring the seller to arrange freight and minimum insurance to the named destination, although cargo risk transfers at loading.
CII Carbon Intensity Indicator:
An International Maritime Organization measure that assigns annual operational carbon-efficiency ratings to qualifying ships, including gas carriers.
CO2 Carbon Dioxide:
An acid-gas component removed from feed gas to prevent freezing in cryogenic equipment and to meet product specifications; it is also a principal combustion-related greenhouse gas.
CO2e Carbon Dioxide Equivalent:
A common unit that converts different greenhouse gases into the amount of carbon dioxide with the same warming effect over a defined period.
COD Commercial Operation Date:
The contractual milestone when a facility has satisfied specified completion and performance conditions and begins normal commercial service.
COQ Certificate of Quality:
A cargo document confirming measured composition, density, heating value, and other quality parameters used for contractual acceptance and energy calculation.
CQQ Certificate of Quantity and Quality:
A formal cargo certificate combining delivered-volume measurements with laboratory or online quality results for custody transfer and invoicing.
CSA Z276 Canadian Standards Association Z276, Liquefied Natural Gas—Production, Storage, and Handling:
The principal Canadian standard establishing safety requirements for facility design, construction, operation, and maintenance.
CTMS Custody Transfer Measurement System:
The integrated tank-gauging, metering, sampling, analysis, and calculation system used to determine the contractual quantity and energy transferred.
CUI Corrosion Under Insulation:
Hidden external corrosion beneath thermal insulation, managed through material selection, coatings, inspection, and moisture-control programs.
CWHE Coil-Wound Heat Exchanger:
A cryogenic exchanger constructed from helically wound tube bundles, widely used as the main exchanger in large liquefaction trains.
D
DAP Delivered at Place:
An Incoterms rule under which the seller delivers cargo ready for unloading at an agreed destination and bears risk to that point.
DCQ Daily Contract Quantity:
The reference daily gas quantity used for nominations, balancing, transportation rights, and supply obligations.
DCT Double Containment Tank:
A storage configuration with a primary liquid container and a secondary liquid-tight outer container, while vapor containment is generally provided by the primary tank roof.
DES Delivered Ex Ship:
A legacy delivery term still widely used in gas trading to describe sales in which the seller provides the vessel and delivers the cargo at the receiving terminal.
DFDE Dual-Fuel Diesel-Electric:
A carrier propulsion arrangement in which engines burn gas or liquid fuel to generate electricity for propulsion and onboard loads.
DMR Dual Mixed Refrigerant:
A liquefaction process using two mixed-refrigerant loops, typically one for precooling and another for liquefaction and subcooling.
DOE United States Department of Energy:
The federal department responsible for public-interest authorizations for natural gas exports to countries without applicable free-trade treatment.
DQT Downward Quantity Tolerance:
A contractual allowance permitting delivered or taken quantities to fall below a base commitment within stated limits and conditions.
DWT Deadweight Tonnage:
The total weight a vessel can safely carry, including cargo, fuel, water, stores, passengers, and crew.
E
ECA Emission Control Area:
A designated maritime region where stricter limits apply to sulfur oxides, nitrogen oxides, or particulate emissions from ships.
EEXI Energy Efficiency Existing Ship Index:
A technical efficiency measure requiring qualifying existing ships to meet design-based carbon-emissions performance criteria.
EN 1473 European Standard 1473, Installation and Equipment for Liquefied Natural Gas—Design of Onshore Installations:
A principal European standard covering the design and safety of onshore liquefaction, storage, transfer, and regasification facilities.
EN 1474 European Standard 1474, Installation and Equipment for Liquefied Natural Gas—Design and Testing of Marine Transfer Systems:
A multipart standard addressing loading arms, transfer hoses, and offshore marine-transfer equipment.
EPC Engineering, Procurement, and Construction:
A project-delivery model under which a contractor assumes integrated responsibility for engineering, equipment and material procurement, construction, and defined completion obligations.
EPCM Engineering, Procurement, and Construction Management:
A delivery model in which a service provider manages design, procurement, and construction while the owner generally holds major supply and construction contracts.
ERC Emergency Release Coupling:
A transfer-system device designed to separate safely under excessive movement or emergency conditions while closing valves to limit cargo release.
ERS Emergency Release System:
The coordinated valves, couplings, controls, and logic that stop transfer and disconnect a ship-to-shore or bunkering connection safely during an emergency.
ESD Emergency Shutdown:
A safety function that automatically or manually places equipment and transfer operations in a safe state when hazardous conditions arise.
ESD-1 Emergency Shutdown Stage 1:
The initial marine-transfer shutdown stage, normally stopping pumps and closing designated valves without disconnecting the transfer system.
ESD-2 Emergency Shutdown Stage 2:
The higher-level marine-transfer response that initiates emergency disconnection after transfer has been stopped and isolation valves have closed.
ETA Estimated Time of Arrival:
The forecast time a carrier will reach a port, anchorage, or berth, used for inventory, pilotage, berth, and unloading planning.
ETD Estimated Time of Departure:
The forecast time a vessel will leave its berth or port, supporting downstream voyage and terminal scheduling.
EU ETS European Union Emissions Trading System:
The cap-and-trade program that places a carbon cost on covered industrial and maritime emissions, affecting European terminals, shipping economics, and cargo value chains.
F
FBOG Forced Boil-Off Gas:
Vapor deliberately generated from cargo to meet propulsion or fuel demand when natural vapor generation is insufficient.
FCT Full Containment Tank:
A storage system whose primary and secondary containers are designed together to contain liquid and control vapor following a credible inner-container failure.
FEED Front-End Engineering Design:
The project phase that defines process configuration, design basis, cost, schedule, execution strategy, and risk sufficiently to support investment and contracting decisions.
FERC Federal Energy Regulatory Commission:
The United States agency responsible for authorizing the siting and construction of onshore and near-shore import or export terminals under the Natural Gas Act.
F&G Fire and Gas:
A detection and alarm system that monitors for flames, heat, smoke, combustible gas, and toxic gas and initiates protective actions.
FGSS Fuel Gas Supply System:
Shipboard equipment that stores, conditions, pressurizes, and delivers gas fuel to engines or boilers at the required temperature and pressure.
FID Final Investment Decision:
The formal approval to commit capital and proceed with project execution after commercial, technical, financing, regulatory, and risk conditions are satisfied.
FLNG Floating Liquefied Natural Gas:
A floating facility that receives and treats gas, liquefies it, stores the cryogenic product, and transfers cargo to carriers.
FMEA Failure Modes and Effects Analysis:
A structured assessment of how equipment or systems can fail, the consequences of each failure, and the safeguards or design changes required.
FOB Free On Board:
A delivery basis under which the buyer normally provides the carrier and assumes cargo risk after loading at the export terminal.
FRU Floating Regasification Unit:
A floating facility equipped to vaporize imported cryogenic cargo, generally without the full storage capability associated with a combined storage-and-regasification vessel.
FSRU Floating Storage and Regasification Unit:
A vessel or barge that receives, stores, and regasifies cargo before delivering natural gas to an onshore network or power plant.
FSU Floating Storage Unit:
A vessel used primarily for offshore or near-shore cryogenic storage, typically paired with separate transfer or regasification facilities.
FTA Free Trade Agreement:
A treaty framework relevant to United States export authorizations because different statutory review requirements apply depending on the destination country’s trade status.
G
GC Gas Chromatograph:
An analyzer that measures gas composition for quality control, process optimization, custody transfer, and heating-value calculation.
GCU Gas Combustion Unit:
Shipboard equipment that safely burns excess vapor when it cannot be used by engines, reliquefied, or retained within cargo-system pressure limits.
GCV Gross Calorific Value:
The heat released by complete combustion when water formed during combustion is condensed, making it a common basis for energy measurement and invoicing.
GERG Groupe Européen de Recherches Gazières:
The European gas research organization associated with widely used equations of state for calculating natural-gas and cryogenic-mixture thermodynamic properties.
GHG Greenhouse Gas:
A gas that traps heat in the atmosphere, including carbon dioxide and methane, and is measured across production, liquefaction, shipping, and regasification.
GIIGNL International Group of Liquefied Natural Gas Importers:
An industry association whose technical publications, statistics, and custody-transfer guidance are widely used by importers, exporters, and terminal operators.
GJ Gigajoule:
An energy unit used in gas contracts, tariffs, terminal throughput reporting, and conversion between regional pricing conventions.
GSA Gas Supply Agreement:
A contract governing feed-gas or sendout-gas quantities, quality, pricing, nominations, delivery points, and supply obligations.
GTT Gaztransport & Technigaz:
A specialist engineering company and technology licensor whose membrane cargo-containment systems are widely used in carriers and onshore or floating storage facilities.
GVU Gas Valve Unit:
A controlled valve assembly that regulates, isolates, vents, and monitors gas supplied to a dual-fuel engine or other consumer.
GWP Global Warming Potential:
A factor comparing the heat-trapping effect of a greenhouse gas with carbon dioxide over a specified time horizon.
H
H2S Hydrogen Sulfide:
A toxic, corrosive acid gas removed from feed gas to protect personnel and equipment and to meet product specifications.
HAZID Hazard Identification:
An early, structured review used to identify major hazards, credible accident scenarios, and risk-reduction needs before detailed design.
HAZOP Hazard and Operability Study:
A systematic, multidisciplinary review of process deviations, causes, consequences, safeguards, and recommendations using guide words and design documentation.
HH Henry Hub:
A United States physical gas hub and benchmark used in domestic gas pricing and many export-cargo price formulas.
HHC Heavy Hydrocarbons:
Higher-molecular-weight hydrocarbon components removed or controlled before liquefaction to prevent freezing, exchanger blockage, and product-quality problems.
HHV Higher Heating Value:
The total heat released by combustion when water vapor in the products is condensed, commonly used for energy content and commercial settlement.
HOA Heads of Agreement:
A preliminary commercial document summarizing principal terms before negotiation and execution of a definitive supply, tolling, or terminal agreement.
I
IACS International Association of Classification Societies:
The association that develops unified maritime requirements applied by major classification societies to gas carriers and floating facilities.
IAPH International Association of Ports and Harbors:
A global port organization that publishes guidance relevant to terminal safety, clean marine fuels, bunkering, and port-call operations.
IECEx International Electrotechnical Commission System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres:
A global conformity-assessment system used to certify equipment and personnel for hazardous locations.
IFV Intermediate Fluid Vaporizer:
A regasification exchanger that transfers heat through an intermediate fluid, isolating seawater or another heat source from the cryogenic process stream.
IGC Code International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk:
The mandatory maritime code governing gas-carrier design, construction, equipment, cargo containment, and safe operation.
IGF Code International Code of Safety for Ships Using Gases or Other Low-Flashpoint Fuels:
The mandatory code establishing safety requirements for ships using gas and other low-flashpoint fuels.
IMO International Maritime Organization:
The United Nations agency responsible for global shipping rules on safety, pollution prevention, vessel efficiency, and crew requirements.
ISM Code International Safety Management Code:
The maritime framework requiring shipping companies and vessels to maintain documented safety-management systems and pollution-prevention procedures.
ISO 16901 International Organization for Standardization 16901, Guidance on Performing Risk Assessment in the Design of Onshore Installations Including the Ship/Shore Interface:
A standard providing methods and principles for assessing major hazards and risk controls.
ISO 16903 International Organization for Standardization 16903, Characteristics Influencing Design and Material Selection:
A technical reference covering cryogenic-fluid properties and their implications for equipment, materials, and facility design.
ISO 16904 International Organization for Standardization 16904, Design and Testing of Marine Transfer Arms for Conventional Onshore Terminals:
A standard defining design, testing, and safety expectations for articulated loading and unloading arms.
ISO 28460 International Organization for Standardization 28460, Ship-to-Shore Interface and Port Operations:
A standard covering compatibility, communications, transfer procedures, and operational safety between carriers and marine terminals.
ISPS Code International Ship and Port Facility Security Code:
The mandatory security framework requiring threat assessments, security plans, access controls, and coordinated measures for vessels and port facilities.
J
JCC Japanese Crude Cocktail:
A weighted average price of crude oil imported into Japan that has historically served as an index in long-term Asian cargo-pricing formulas.
JKM Japan Korea Marker:
A widely used price assessment for spot cargoes delivered to Northeast Asia and a benchmark for physical trading, derivatives, and contract indexation.
JT Joule–Thomson:
The temperature-change effect caused by throttling a real gas through a valve or restriction, used in refrigeration, pressure letdown, and process design.
L
LCA Life-Cycle Assessment:
A method for quantifying environmental impacts across gas production, processing, liquefaction, transport, regasification, distribution, and end use.
LBV Liquefied Natural Gas Bunkering Vessel:
A purpose-built vessel that delivers cryogenic marine fuel to receiving ships, usually through ship-to-ship transfer.
LEL Lower Explosive Limit:
The minimum fuel concentration in air capable of propagating combustion, used to set gas-detector alarms and hazardous-area controls.
LFL Lower Flammability Limit:
The lowest gas concentration in air that can sustain flame propagation under specified conditions.
LHV Lower Heating Value:
The heat released by combustion when water remains as vapor, commonly used for equipment-efficiency and fuel-consumption calculations.
LIMUM Linde Multi-Stage Mixed Refrigerant:
A liquefaction technology using staged mixed-refrigerant cooling to improve process integration and efficiency across selected plant scales.
LLE Long-Lead Equipment:
Major items with extended engineering, manufacturing, or delivery schedules, such as cryogenic exchangers, compressors, turbines, tanks, and loading arms.
LNG Liquefied Natural Gas:
Natural gas cooled to a cryogenic liquid for efficient storage and marine transport, normally at near-atmospheric pressure.
LNGC Liquefied Natural Gas Carrier:
A specialized ship designed with insulated cryogenic containment, cargo-handling systems, and gas-management equipment.
LNGRV Liquefied Natural Gas Regasification Vessel:
A carrier equipped with onboard vaporizers and high-pressure sendout systems that can deliver regasified cargo directly to a receiving network.
LOA Length Overall:
A vessel’s maximum bow-to-stern length, used in berth compatibility, turning-basin, tug, and mooring assessments.
LOPA Layer of Protection Analysis:
A semi-quantitative method for evaluating whether independent protection layers reduce process-event risk to an acceptable level.
LTA Liquefaction Tolling Agreement:
A contract under which a customer supplies or procures feed gas and pays a facility owner for liquefaction and related services.
M
MARAD United States Maritime Administration:
The federal agency that coordinates review and licensing of offshore deepwater ports in conjunction with the Coast Guard and other authorities.
MARPOL International Convention for the Prevention of Pollution from Ships:
The principal international convention controlling ship-source air emissions, discharges, waste, and other forms of marine pollution.
MBL Minimum Breaking Load:
The minimum force at which a new mooring line or component is expected to fail under specified test conditions.
MCHE Main Cryogenic Heat Exchanger:
The core exchanger in a liquefaction train where treated feed gas is cooled, liquefied, and often subcooled against refrigerant circuits.
MCR Maximum Continuous Rating:
The highest power output at which a marine or plant engine is designed to operate continuously under specified conditions.
MDEA Methyldiethanolamine:
A selective amine solvent commonly used to remove carbon dioxide and hydrogen sulfide from feed gas.
MDO Marine Diesel Oil:
A distillate or blended marine fuel used for pilot injection, backup operation, or dual-fuel propulsion.
MEG4 Mooring Equipment Guidelines, Fourth Edition:
An industry reference for tanker and terminal mooring-system design, inspection, line management, and operational safety.
ME-GI M-Type Electronically Controlled Gas Injection:
A high-pressure, two-stroke dual-fuel marine engine technology used by modern carriers for efficient gas-fueled propulsion.
MFC Mixed Fluid Cascade:
A liquefaction process using multiple mixed-fluid refrigeration cycles arranged in cascade to provide staged cooling and liquefaction.
MFM Mass Flow Meter:
An instrument that measures fluid mass flow directly and may be used for fuel, vapor, process, or transfer measurement.
MGO Marine Gas Oil:
A low-viscosity distillate marine fuel used for pilot fuel, port operation, backup, or regulatory compliance.
MLA Marine Loading Arm:
An articulated pipe system that transfers cryogenic liquid or vapor between a terminal and a carrier while accommodating vessel movement.
MMBtu One Million British Thermal Units:
The standard energy unit for many international gas prices, contract quantities, tolls, and shipping-cost comparisons.
MMscfd Million Standard Cubic Feet per Day:
A daily gas-flow unit used for feed-gas supply, plant capacity, fuel use, and regasification sendout.
MN Methane Number:
A measure of a gaseous fuel’s resistance to engine knock, used to assess compatibility with gas-fueled engines.
MR Mixed Refrigerant:
A tailored blend of refrigerant components selected to match the cooling curve of natural gas and improve liquefaction efficiency.
MRC Mixed Refrigerant Cycle:
A refrigeration cycle using a multicomponent working fluid to provide cooling across a broad cryogenic temperature range.
MRU Mercury Removal Unit:
A feed-treatment system that removes trace mercury to prevent aluminum corrosion and contamination of cryogenic equipment.
MRV Monitoring, Reporting, and Verification:
A structured emissions-accounting framework used to collect, disclose, and independently verify greenhouse-gas or methane performance data.
MSPA Master Sale and Purchase Agreement:
A framework contract establishing standard legal and commercial terms for multiple spot or short-term cargo transactions.
MTPA Million Tonnes per Annum:
The principal annual capacity unit for liquefaction plants, receiving terminals, and portfolio supply volumes.
N
N2 Nitrogen:
A noncombustible feed-gas component that reduces heating value and may require rejection to meet product specifications or control liquefaction energy use.
NBP National Balancing Point:
The United Kingdom’s virtual gas-trading hub and a benchmark used in European gas and cargo pricing.
NBOG Natural Boil-Off Gas:
Vapor generated naturally by unavoidable heat ingress into a carrier or storage tank.
NCV Net Calorific Value:
The heat released by complete combustion when water remains in vapor form, equivalent in concept to lower heating value.
NEPA National Environmental Policy Act:
The United States law requiring federal agencies to assess environmental effects and alternatives for major projects requiring federal action.
NFPA 59A National Fire Protection Association 59A, Standard for the Production, Storage, and Handling of Liquefied Natural Gas:
A foundational safety standard used for facility siting, design, fire protection, transfer, operation, and maintenance.
NGA Natural Gas Act:
The United States statute underpinning federal authorization of interstate natural-gas facilities, onshore terminals, and gas imports and exports.
NGL Natural Gas Liquids:
Hydrocarbon liquids recovered during feed-gas processing or heavy-component removal, including ethane, propane, butanes, and natural gasoline.
NOR Notice of Readiness:
A vessel’s formal notice that it has arrived and is ready to load or discharge, often affecting laytime and contractual performance calculations.
NOx Nitrogen Oxides:
Combustion pollutants controlled through burner, turbine, engine, and maritime-emissions standards.
NPSH Net Positive Suction Head:
A pump-design parameter used to ensure sufficient inlet pressure and prevent cavitation in cryogenic transfer and sendout service.
NRU Nitrogen Rejection Unit:
A cryogenic separation unit that removes nitrogen from natural gas to meet heating-value and product-composition requirements.
O
OCIMF Oil Companies International Marine Forum:
A maritime industry association whose inspection, mooring, terminal, and ship-management guidance is widely applied to gas-carrier operations.
OCP Optimized Cascade Process:
A liquefaction technology using optimized propane, ethylene, and methane refrigeration stages to cool and liquefy treated gas.
OGMP 2.0 Oil and Gas Methane Partnership 2.0:
A United Nations-led reporting framework that promotes source-level methane measurement, transparent inventories, and reduction targets across operated and non-operated assets.
ORV Open Rack Vaporizer:
A seawater-heated exchanger commonly used for high-capacity regasification at coastal receiving terminals.
P
PCHE Printed Circuit Heat Exchanger:
A compact, diffusion-bonded exchanger capable of handling high pressures and steep temperature gradients in cryogenic and floating applications.
PERC Powered Emergency Release Coupling:
An actively operated coupling that isolates and separates a marine loading arm during emergency disconnection.
PFHE Plate-Fin Heat Exchanger:
A compact aluminum exchanger providing efficient multistream heat transfer in liquefaction, natural-gas-liquid recovery, and subcooling service.
PHMSA Pipeline and Hazardous Materials Safety Administration:
The United States agency that administers federal safety rules for regulated onshore facilities and associated gas pipelines.
P&ID Piping and Instrumentation Diagram:
A detailed engineering drawing showing process equipment, piping, valves, instruments, control loops, and safeguarding functions.
PRICO Poly Refrigerant Integrated Cycle Operations:
A single mixed-refrigerant liquefaction process often selected for smaller, modular, floating, or peak-shaving facilities.
PSA Pressure Swing Adsorption:
A gas-separation process that cycles adsorbent beds between pressure levels to remove selected contaminants or recover purified gas.
PSM Process Safety Management:
A management system for controlling major hazards through design integrity, operating procedures, competency, mechanical integrity, change control, and incident learning.
PSV Pressure Safety Valve:
A self-actuating relief device that protects equipment and piping from pressure above the allowable limit.
PTS Pipe-to-Ship:
A bunkering method in which marine fuel is transferred to a vessel through a fixed terminal or jetty pipeline.
Q
QC/DC Quick Connect/Disconnect:
A coupling system enabling rapid, controlled attachment and detachment of cryogenic transfer hoses or loading equipment.
QRA Quantitative Risk Assessment:
A numerical analysis of accident frequencies and consequences used for siting, layout, exclusion zones, and risk-reduction decisions.
R
RAB Regulated Asset Base:
The approved value of infrastructure on which a regulated terminal or network operator may earn a return through tariffs.
RAM Reliability, Availability, and Maintainability:
An engineering analysis used to predict production uptime, identify system bottlenecks, optimize sparing, and support throughput guarantees.
RBI Risk-Based Inspection:
An asset-integrity method that prioritizes inspection scope and frequency according to equipment failure probability and consequence.
REMIT Regulation on Wholesale Energy Market Integrity and Transparency:
The European Union framework prohibiting insider trading and market manipulation in wholesale energy markets and imposing reporting obligations on participants.
RFSU Ready for Start-Up:
A project milestone indicating that construction, pre-commissioning, system checks, and required approvals have progressed sufficiently to introduce process fluids.
RKM Revised Klosek–McKinley:
A calculation method used to determine cryogenic cargo density from composition and temperature for custody-transfer quantity calculations.
RLNG Regasified Liquefied Natural Gas:
Natural gas produced by vaporizing imported cryogenic liquid for delivery into a pipeline network or directly to an end user.
RPT Rapid Phase Transition:
A physical explosion that can occur when cryogenic liquid contacts water and undergoes extremely rapid vaporization without combustion.
S
SCF Standard Cubic Foot:
A gas-volume unit referenced to defined standard temperature and pressure conditions, which must be stated to ensure comparable measurements.
SCT Single Containment Tank:
A storage configuration in which the primary container holds the cryogenic liquid and the outer structure generally does not provide full secondary liquid containment.
SCV Submerged Combustion Vaporizer:
A regasification unit that passes hot combustion gases through a water bath surrounding product tubes, providing flexible and reliable peak sendout.
SDMBL Ship Design Minimum Breaking Load:
The specified mooring-line strength used as the reference point for designing and managing a ship’s mooring system.
SEC Specific Energy Consumption:
The energy required per unit of production or regasified output, used to compare train efficiency, operating performance, and technology options.
SEEMP Ship Energy Efficiency Management Plan:
A required ship-specific plan for improving and documenting operational energy efficiency and carbon performance.
SGMF Society for Gas as a Marine Fuel:
An industry body that develops technical guidance and promotes safe use, bunkering, and handling of gas and low-flashpoint marine fuels.
SIF Safety Instrumented Function:
A defined sensor, logic-solver, and final-element function that moves a process to a safe state when specified conditions occur.
SIGTTO Society of International Gas Tanker and Terminal Operators:
A leading industry organization publishing operational and technical guidance for gas carriers, terminals, cargo transfer, and ship-shore compatibility.
SIL Safety Integrity Level:
A discrete measure of risk reduction required from a safety instrumented function, determined through hazard and protection-layer analysis.
SIMOPS Simultaneous Operations:
Concurrent activities whose interaction can create additional risk, such as cargo transfer, bunkering, commissioning, construction, or maintenance.
SIRE Ship Inspection Report Programme:
A standardized tanker and gas-carrier inspection regime used by charterers and terminal operators to support vessel-assurance decisions.
SIS Safety Instrumented System:
An independent system of sensors, logic solvers, and final control elements that executes one or more protective functions.
SMR Single Mixed Refrigerant:
A liquefaction configuration using one multicomponent refrigerant loop, favored for relative simplicity and compact plant layouts.
SOF Statement of Facts:
A chronological record of port-call and cargo-operation events used to calculate laytime, delays, and contractual claims.
SOLAS International Convention for the Safety of Life at Sea:
The principal global treaty governing merchant-ship construction, equipment, operation, fire safety, navigation, and emergency preparedness.
SOx Sulfur Oxides:
Air pollutants produced by burning sulfur-containing fuels and controlled through marine fuel-sulfur limits and emission-control rules.
SPA Sale and Purchase Agreement:
The definitive contract governing cargo quantity, quality, price, delivery, scheduling, credit, liability, and default obligations.
SSL Ship-Shore Link:
The communications and control connection that exchanges transfer-status information and coordinated shutdown signals between a carrier and terminal.
STCW International Convention on Standards of Training, Certification and Watchkeeping for Seafarers:
The global framework setting competency, certification, and watchkeeping requirements for personnel serving on ships, including gas carriers.
STS Ship-to-Ship:
The transfer of cryogenic cargo or marine fuel directly between two vessels using hoses, fenders, mooring systems, and coordinated safety procedures.
STV Shell-and-Tube Vaporizer:
A conventional exchanger that regasifies cryogenic liquid using steam, hot water, glycol-water, or another heating medium.
SWL Safe Working Load:
The maximum load that lifting, transfer, or mooring equipment may carry safely under stated operating conditions.
T
Tcf Trillion Cubic Feet:
A gas-volume unit used for resource bases, long-term supply commitments, and large-scale market balances.
TEG Triethylene Glycol:
A hygroscopic liquid used to remove water vapor from natural gas before downstream processing or cryogenic cooling.
TFDE Tri-Fuel Diesel-Electric:
A carrier propulsion system whose generating engines can operate on gas and more than one grade of liquid marine fuel.
TMSA Tanker Management and Self Assessment:
A management-system framework used by vessel operators to assess and improve safety, environmental, maintenance, and operational performance.
ToP Take-or-Pay:
A contractual mechanism requiring payment for a minimum committed quantity whether or not the buyer physically takes it, subject to specified relief and make-up rights.
TPA Third-Party Access:
A regulatory or contractual regime allowing qualifying users to obtain terminal or network capacity on defined transparent and nondiscriminatory terms.
TSA Temperature Swing Adsorption:
A purification process in which adsorbent beds remove water or contaminants at low temperature and are regenerated by heating.
TSA Terminal Services Agreement:
A contract defining storage, berthing, unloading, regasification, sendout, scheduling, tariff, and operating services provided by a terminal.
TSA Tolling Services Agreement:
A contract under which a facility processes customer-provided feed gas or capacity entitlement in return for fixed and variable service payments.
TTF Title Transfer Facility:
The Netherlands’ virtual gas-trading hub and the principal benchmark for continental European gas and many delivered cargo transactions.
TTS Truck-to-Ship:
A bunkering method in which cryogenic marine fuel is delivered directly from road tankers to a receiving vessel.
TTW Tank-to-Wake:
The portion of marine-fuel emissions produced from onboard fuel use through propulsion, including combustion emissions and methane slip.
TUA Terminal Use Agreement:
A contract granting rights to berth, unload, store, regasify, and deliver gas through a receiving terminal subject to capacity and operating rules.
U
UEL Upper Explosive Limit:
The maximum fuel concentration in air above which a mixture is too rich to propagate combustion under specified conditions.
UFL Upper Flammability Limit:
The highest gas concentration in air that can sustain flame propagation under specified test conditions.
UIOLI Use-It-or-Lose-It:
A capacity-management rule under which persistently unused contracted terminal or network capacity may be withdrawn or reallocated.
UKC Under-Keel Clearance:
The vertical distance between a vessel’s keel and the seabed or channel bottom, critical to safe carrier access and berth planning.
UQT Upward Quantity Tolerance:
A contractual allowance permitting quantities above the base annual or cargo commitment within agreed limits.
USCG United States Coast Guard:
The federal maritime authority responsible for vessel safety, waterfront-facility oversight, security, navigation, and deepwater-port reviews.
USM Ultrasonic Meter:
A flow meter that measures gas velocity using sound-transit times and is widely used for high-capacity sendout and custody-transfer service.
V
VCE Vapor Cloud Explosion:
An explosion resulting from ignition of a flammable vapor cloud where congestion, confinement, or turbulence produces damaging overpressure.
VOC Volatile Organic Compound:
An organic chemical that readily evaporates and may be regulated because of air-quality, occupational-health, or environmental impacts.
W
WI Wobbe Index:
A measure relating heating value to relative density that indicates whether gases can be interchanged in combustion equipment without major changes in heat input.
WTT Well-to-Tank:
The portion of a marine-fuel life cycle covering production, processing, liquefaction, transport, storage, and delivery to the vessel’s fuel tank.
WTW Well-to-Wake:
The complete marine-fuel emissions boundary combining upstream fuel production and delivery with onboard use and propulsion.
X
X-DF X-Series Dual-Fuel:
A low-pressure, two-stroke dual-fuel marine engine technology used on modern carriers and gas-fueled ships.