LNG System Suppliers

LNG systems cover the cryogenic containment, cargo handling, boil-off gas management, and fuel supply equipment that LNG carriers and LNG-fueled vessels rely on. LNG (Liquefied Natural Gas) is primarily methane (CH4 typically over 85%) stored at -162°C cryogenic temperature at atmospheric pressure. The LNG system suppliers listed on Records Marine cover the OEM and authorised distributor channels for LNG carriers (Q-Max, Q-Flex, conventional 174,000 m³) and the rapidly growing fleet of LNG-fueled vessels including container ships, ferries, cruise vessels, and bunker carriers.

The procurement decision spans containment system selection (membrane, Moss spherical, IHI SPB, Type C for small LNG), cargo handling capacity (cryogenic compressors and deepwell pumps), reliquefaction or boil-off gas (BOG) handling strategy, and the integration with ME-LGIM dual-fuel propulsion or pure gas engines. Picking the right LNG system suppliers means matching equipment specification to vessel containment philosophy, trading pattern, and the IGC Code (for carriers) or IGF Code (for LNG-fueled vessels) compliance scope.

What LNG Systems Cover Onboard

Marine LNG systems break across several integrated equipment groups:

• LNG cargo containment - membrane systems (GTT Mark III, NO96), Moss spherical tanks, IHI SPB tanks, or Type C pressure-temperature vessels for smaller installations. Each containment technology has dedicated material, insulation, and structural requirements under the IGC Code.
• Cryogenic cargo handling - deepwell LNG pumps mounted inside the tank, booster pumps, cryogenic transfer arms, and cargo manifold sized for the low temperature service.
• Boil-off gas (BOG) management - the central challenge on LNG carriers. BOG is captured, used as fuel in dual-fuel engines (most LNG carriers run on BOG), reliquefied back to cargo, or thermally oxidised in gas combustion units (GCU).
• Reliquefaction plants - on LNG carriers using compression-cycle reliquefaction (typically nitrogen refrigerant on smaller installations or mixed refrigerant on large vessels).
• LNG fuel supply systems (FSS) - on LNG-fueled vessels with ME-LGIM, X-DF, or pure gas engines, the fuel supply system handles bunker storage, vaporiser, fuel preparation, and gas valve unit (GVU).
• LNG bunkering arrangements onboard - bunker manifold, ESD systems, and the receiver-side equipment for vessels taking LNG bunkers (the bunkering operation itself is coordinated through port agency channels).
• Cargo measurement and custody transfer - level and temperature sensors (cryogenic-rated), radar gauges, custody transfer measurement systems (CTMS) for cargo accounting.

LNG Cargo Containment Systems

LNG containment splits across four main technology families under IGC Code Chapter 4:

• Membrane systems - thin metal membrane (Invar or stainless steel) directly supporting LNG cargo at -162°C, backed by insulation and the inner hull as load-bearing structure. GTT (Gaztransport & Technigaz) supplies the dominant designs: Mark III (corrugated stainless steel), Mark III Flex (improved insulation), NO96 (Invar), NO96 GW. Membrane systems dominate large LNG carrier newbuilds.
• Moss spherical tanks - independent aluminium spherical tanks supported on a cylindrical skirt, with polyurethane foam insulation. Moss Maritime (now Equinor) designed the original system; used on Norwegian-built and many Japanese-built LNG carriers. Limited new builds in recent years but large in-service fleet.
• IHI SPB tanks (Self-supporting Prismatic-shape IMO type B) - prismatic self-supporting tanks similar to Type B classification. Used on selected LNG carriers and LNG bunker vessels.
• Type C tanks for small LNG and LNG fuel - pressure-temperature vessels (rated 4-7 bar / -163°C) used on small LNG carriers, LNG bunker vessels, and LNG fuel storage on LNG-fueled vessels. Vacuum-insulated or polyurethane-insulated designs.

Each containment system carries its own approval scope from class societies (DNV, ABS, Lloyd's Register, Bureau Veritas, RINA, ClassNK, KR, CCS) and the original technology licensor.

LNG Cargo Handling Equipment

Cryogenic cargo handling adds complexity beyond the LPG equivalent because of the -162°C operating temperature:

• Cryogenic deepwell pumps - submersible pumps mounted inside the cargo tank operating at LNG temperature. Ebara, Nikkiso (formerly Lewa Nikkiso), Cryostar, and Vanzetti Engineering supply the main brands. Pumps include their own seal cooling and motor cooling design suited to cryogenic service.
• Booster pumps - high-head pumps used at cargo discharge to match shore terminal pressure requirements.
• Cryogenic compressors - centrifugal and reciprocating compressors handling LNG vapor for BOG management, fuel gas conditioning, and reliquefaction service.
• Cargo vaporisers - shell-and-tube heat exchangers vaporising LNG for fuel gas supply to engines or for tank pressure management.
• Cryogenic valves and piping - vacuum-insulated lines, cryogenic ball valves, globe valves with extended bonnet and specialty seat materials suited to -162°C service.

Boil-Off Gas (BOG) Management and Reliquefaction

BOG management is the defining technical challenge of LNG cargo handling. Even with the best insulation, ambient heat ingress vaporises 0.1-0.15% of LNG cargo per day. The cargo gas must be managed:

• Used as engine fuel - most LNG carriers run on BOG via ME-GI dual-fuel engines, Wartsila X-DF, or pure gas turbines. The fuel consumption typically matches or exceeds natural BOG rate.
• Reliquefaction onboard - on Q-Max and Q-Flex Qatari carriers and some other large LNG carriers, an onboard reliquefaction plant re-condenses BOG to liquid and returns it to cargo tanks. Reliquefaction adds capital cost but eliminates cargo loss on long voyages.
• Gas combustion unit (GCU) - thermal oxidiser burning excess BOG safely when not needed for fuel or reliquefaction. Required on most LNG carriers under IGC Code.
• Vent to atmosphere - emergency only, under MARPOL and IMO methane slip restrictions.

LNG Fuel Systems and Propulsion

LNG-fueled vessels are the fastest-growing application for LNG system suppliers. The propulsion options:

• MAN ES ME-GI (Man-B&W ME-engine with Gas Injection) - high-pressure dual-fuel 2-stroke with LNG injection at 300 bar plus pilot fuel. Common on LNG carriers and large LNG-fueled container vessels.
• Wartsila X-DF (Dual Fuel) - low-pressure dual-fuel 2-stroke with port admission LNG. Used on LNG carriers, container ships, and large bulk carriers.
• Wartsila DF 4-stroke engines - medium-speed dual-fuel engines for ferries, offshore vessels, and auxiliary power.
• MAN ME-LGIM - the methanol equivalent (different fuel - included for clarity).
• Pure gas engines - some LNG-fueled vessels use spark-ignited gas-only engines (Rolls-Royce Bergen, Wartsila SG).

The LNG fuel supply system (FSS) handles bunker storage (Type C tanks typically), vaporiser, GVU (gas valve unit), and fuel preparation between storage and engine. The IGF Code (International Code of Safety for Ships using Gases or other Low-flashpoint Fuels) governs LNG-fueled vessel design.

Major LNG System Brands and OEMs

The LNG system market concentrates around several major OEM brands:

• GTT (Gaztransport & Technigaz) - dominant membrane containment licensor (Mark III, NO96)
• Moss Maritime - Moss spherical tank technology
• IHI - SPB prismatic tank design and Japanese newbuild LNG carriers
• Wartsila Gas Solutions (formerly Hamworthy LNG) - cargo handling, reliquefaction, fuel gas systems
• Cryostar - cryogenic pumps, compressors, vaporisers
• MAN Energy Solutions - ME-GI dual-fuel engines and complete LNG fuel supply systems
• Ebara and Nikkiso (Lewa Nikkiso) - cryogenic deepwell and booster pumps
• TGE Marine - small LNG tank engineering and complete cargo system design
• Burckhardt Compression - high-pressure piston compressors for ME-GI fuel gas service
• Cargotec MacGregor and other shipyards integrating complete LNG fuel solutions on newbuild containerships and cruise vessels

Choosing an LNG System Supplier

Picking among LNG system suppliers requires matching equipment specification to vessel containment system, trading pattern, and the IGC or IGF Code compliance scope:

• Containment system licensor authorisation - GTT membrane work requires GTT-licensed fabrication; Moss tank work requires Moss Maritime authorisation. Confirm the supplier holds the appropriate licensor relationship.
• Vessel type and trade pattern match - large LNG carriers (Q-Max, Q-Flex, conventional 174k m³) with membrane containment vs. LNG bunker vessels with Type C tanks vs. LNG-fueled container ships using Type C fuel storage. Each scope drives different supplier capabilities.
• IGC Code and IGF Code compliance documentation - cargo carrier work falls under IGC Code; LNG-fueled vessel work falls under IGF Code. Both require Class society approval (DNV, ABS, Lloyd's Register, Bureau Veritas, RINA, ClassNK, KR, CCS).
• Cargo handling capacity match - cryogenic pump and compressor sizing matched to cargo loading rate, voyage profile, and discharge requirements.
• BOG management strategy - reliquefaction plant supplier match (capital cost) vs. BOG-as-fuel strategy (operating fuel consumption). The decision affects equipment selection across the entire system.
• Spare parts and lifecycle support - LNG cargo systems run for the vessel's full service life; supplier should have authorised LNG system spare parts support across operational years.

Need LPG containment (Type A prismatic, Type C pressure tanks) and propane/butane cargo handling instead? See LPG system suppliers for that distinct technical scope.

Frequently Asked Questions

What is the difference between LNG and LPG systems?

LNG (Liquefied Natural Gas) is methane stored at -162°C cryogenic temperature at atmospheric pressure, requiring membrane (GTT Mark III, NO96), Moss spherical, IHI SPB, or Type C cryogenic containment with heavy vacuum or polyurethane insulation. LPG (Liquefied Petroleum Gas) is propane and butane stored at -42°C fully refrigerated or under semi-pressure 5-20 bar, using Type A prismatic or Type C pressure tanks. The containment technology, brand landscape (GTT/Moss vs Wartsila Hamworthy/TGE), handling equipment, and regulatory scope differ accordingly.

What containment systems does LNG use?

LNG containment uses four main technologies under IGC Code Chapter 4: Membrane systems (GTT Mark III and NO96 - dominant on large LNG carriers); Moss spherical tanks (large in-service fleet, fewer new builds); IHI SPB tanks (specialised LNG carriers and LNG bunker vessels); Type C pressure-temperature tanks (small LNG carriers, LNG bunker vessels, and LNG fuel storage on LNG-fueled vessels). Containment choice drives BOG handling architecture, insulation design, and complete cargo system specification.

What is BOG (boil-off gas) on LNG carriers?

BOG (Boil-off Gas) is the natural gas vapor that forms continuously as ambient heat penetrates the LNG cargo tank insulation, vaporising a fraction of the cargo. Even with best-in-class insulation, BOG rate typically runs 0.1-0.15% of cargo volume per day on modern LNG carriers. BOG is managed by: using it as engine fuel (ME-GI, X-DF, or pure gas engines); reliquefying it onboard and returning to cargo tanks; thermally oxidising in gas combustion units (GCU). BOG management strategy drives major equipment decisions across the LNG cargo system.

What is ME-GI propulsion?

ME-GI (Man-B&W ME-engine with Gas Injection) is MAN Energy Solutions' high-pressure dual-fuel 2-stroke engine running on LNG as primary fuel with marine diesel pilot ignition. The engine injects LNG at approximately 300 bar directly into the combustion chamber. ME-GI dominates the LNG carrier propulsion market and large LNG-fueled container vessels (Maersk, CMA CGM newbuilds). The companion ME-LGIM runs on methanol; ME-LGIP runs on LPG. Wartsila's X-DF is the low-pressure dual-fuel alternative.