LNG Pumps

LNG Pumps for Cryogenic Marine Fuel and Cargo Handling

DESMI LNG pumps are developed for marine environments where cryogenic liquid handling must be reliable, efficient and carefully controlled. In LNG service, the pump is part of a larger system that may include storage tanks, cargo lines, bunker arrangements, conditioning systems and safety barriers. A suitable LNG pump must therefore match both the process duty and the vessel design.

For LNG fuel service, the focus is often on stable transfer from tank to fuel supply system, compact installation and support for alternative-fuel vessel concepts. For LNG cargo handling, priorities typically include high-capacity transfer, dependable operation during loading and unloading, and robust performance as part of the cargo system on LNG carriers and bunker vessels. DESMI addresses both areas through a combination of deepwell pumps for direct tank-based transfer and magnetically driven pump solutions for leakage-sensitive duties, where total containment is a key design objective.

DESMI LNG Pumps Range for Fuel, Cargo and Leakage-Sensitive Duties

DESMI’s LNG-capable range includes dedicated deepwell and booster solutions for cryogenic marine service, as well as magnetically driven pump families for duties where low leakage or sealless operation is essential. This enables engineering teams to select an LNG pump concept according to tank arrangement, duty point, risk profile and maintenance strategy.

• DesFuel Deepwell Pump (RSL) - designed for alternative fuels, including LNG, and suited to fuel-related cryogenic duties on a wide range of vessels.
  

• DesCargo Booster Pump (NDB) - supports LNG-related booster service within cargo and transfer systems.

• DesCargo Deepwell Pump (NDW) - developed for liquefied gas cargo handling, including LNG carrier and bunker vessel applications.

• NSL Centrifugal Pump - Magnetically Driven - a sealless centrifugal pump family for leakage-sensitive liquid handling.

• ESL Centrifugal Pump - Magnetically Driven - suited to applications where containment and low maintenance are priorities.

• TSL Centrifugal Pump - Magnetically Driven - supports demanding process duties with magnetic drive containment benefits.

• MV Multistage Centrifugal Pump - Magnetically Driven - available for system duties requiring multistage pressure performance with sealless operation.
  
  

Deepwell designs are directly suited to LNG service where the pump is installed in, or closely associated with, the tank for loading, unloading and transfer of cryogenic liquid. Magnetic drive pumps serve a different but highly relevant role. They are particularly valuable in leakage-sensitive duties, where eliminating the shaft seal to atmosphere can support safer handling of hazardous or sensitive media. When reviewing project requirements, DESMI helps determine whether a deepwell LNG pump, a booster pump or a magnetically driven centrifugal pump is the right technical fit.

Applications for LNG Pumps Across Vessels and Cryogenic Systems

LNG pumps are used across a range of vessel types and cryogenic systems where liquefied natural gas must be transferred, circulated or boosted safely. In marine settings, this includes both vessels that consume LNG as fuel and vessels that transport LNG as cargo. The duty profile depends on whether the pump supports fuel conditioning, cargo movement, bunkering or internal transfer between tanks and process points.

Typical applications include:

• LNG carriers handling loading, unloading and cargo transfer duties

• Bunker vessels supplying LNG to receiving ships

• Gas carriers and chemical tankers with cryogenic or liquefied gas duties

• Alternative-fuel marine systems using LNG as part of the onboard fuel architecture

• Tank transfer and circulation in cryogenic liquid systems

• Booster service where additional pressure is required in the transfer line

For example, a deepwell pump may be selected for tank-based unloading on an LNG carrier, while a magnetically driven centrifugal pump may be considered for a low-leakage auxiliary duty elsewhere in the system. This distinction matters because the application environment, accessibility and operating mode can vary significantly between cargo tanks, bunker skids and fuel preparation systems. DESMI’s LNG pump offering is structured to support these different use cases without forcing a single pump concept on to every system.

Why Cryogenic Pump Selection Matters for Safety, Uptime and Efficiency

Choosing the right cryogenic pump affects more than hydraulic performance. In LNG service, the pump contributes directly to safety, operational continuity and the economics of the vessel or installation. Cryogenic liquids impose stresses on materials, seals, clearances and rotating components that conventional pumping duties do not. A pump that performs well at ambient conditions is not automatically suitable as a centrifugal pump for cryogenic liquids.

From a safety perspective, leakage prevention is a primary concern. LNG is handled at very low temperature and requires careful containment in fuel and cargo systems. Pump concepts that reduce leakage risk can simplify system design priorities and lower operational exposure. From an uptime perspective, stable performance at cryogenic temperatures is essential to avoid process interruptions during transfer, bunkering or cargo discharge.

Maintenance strategy is also a major selection factor. Sealless magnetic drive pump technology can reduce maintenance linked to shaft seals, while deepwell configurations can be advantageous where direct tank service is required. Energy efficiency should also be considered, especially in systems with frequent operation or high transfer volumes. Over time, correct pump selection helps reduce downtime, supports predictable service planning and lowers total cost of ownership across the asset lifecycle.

Key value drivers in LNG pump selection:

• Leak prevention and improved containment of cryogenic media

• Stable operation at LNG temperatures

• Reliable marine duty performance in continuous or intermittent service

• Lower maintenance requirements in the right design concept

• Efficient hydraulic performance and reduced operating cost

• Better system integration with vessel layout and service access constraints

Deepwell and Magnetic Drive Design Principles for Cryogenic Liquids

DESMI’s LNG pump portfolio is based on two distinct technical principles: deepwell pump design for direct tank-related transfer and magnetic drive pump technology for sealless, low-leakage operation. Each principle addresses a different operational need within cryogenic liquid handling.

A deepwell pump is typically used where the pump must transfer liquefied gas directly from a tank or cargo space. In marine LNG service, this makes the concept highly relevant for loading, unloading and internal transfer duties on gas carriers, LNG carriers and bunker vessels. The design supports efficient extraction and movement of cryogenic liquid while fitting within the vessel’s cargo or fuel tank arrangement.

A magnetic drive pump uses magnetic coupling instead of a conventional shaft seal to atmosphere. This creates a sealless pump for cryogenic liquid or other hazardous media duties where leakage cannot be accepted. DESMI’s NSL, ESL, TSL and MV pump families are documented as magnetically driven solutions for containment-focused applications. Depending on project requirements, such designs can support safer operation, lower seal-related maintenance and improved environmental control.

These two principles are not interchangeable in every installation. Deepwell pumps are generally the natural choice for direct tank-based LNG transfer, while magnetic drive pumps are relevant where total containment and low external leakage risk are key selection criteria. DESMI helps engineering teams assess which pump architecture best aligns with duty conditions, installation envelope and service philosophy.

LNG Pumps Technical Capabilities: Temperature, Capacity and System Fit

Technical selection of LNG pumps should always begin with the actual duty point and system architecture. In cryogenic service, the main parameters usually include operating temperature, required flow, discharge pressure, NPSH conditions, wetted materials, installation orientation and available maintenance access. A suitable LNG pump must function as part of the whole system, not just as an isolated hydraulic component.

For LNG-related applications, a key reference point is suitability down to around -165°C. This is the temperature range that typically defines LNG service and influences materials, tolerances and testing requirements. DESMI documents this temperature relevance clearly for selected deepwell models, including the RSL and NDW product lines. Depending on the specific pump type, project teams should also review expected flow rates, operating heads and system pressure margins.

Examples of important technical selection factors include:

• Temperature range - cryogenic suitability for LNG-related duties around -165°C

• Flow and capacity - matched to fuel transfer, cargo discharge, booster duty or circulation requirements

• Pressure and head - based on line losses, tank arrangement and process demands

• NPSH conditions - especially important in low-temperature systems where cavitation margin must be carefully assessed

• Material compatibility - selected for cryogenic liquid handling and service life under marine conditions

• Installation constraints - space, orientation, access and integration with onboard systems

As one documented example, the DesCargo Deepwell Pump (NDW) is presented with capacities up to 1200 m³/h, pressure up to 250 mLC and temperature suitability down to -165°C for LNG-related duty. That makes it relevant for engineering teams seeking a cryogenic centrifugal pump concept for marine cargo transfer applications.

Product Spotlight: DesFuel RSL and DesCargo NDW for LNG Duty

Among DESMI’s best-documented LNG pump models, the DesFuel Deepwell Pump (RSL) and the DesCargo Deepwell Pump (NDW) are particularly relevant for marine projects involving LNG as fuel or cargo. Both are deepwell designs, but they address different operational contexts.

DesFuel Deepwell Pump (RSL) is positioned for alternative-fuel duty across a broad vessel spectrum. It is designed for fuels including LNG, ammonia, LPG/LEG and methanol/ethanol, which makes it attractive for owners and designers seeking fuel flexibility or a degree of platform standardisation across alternative-fuel projects. The RSL pump has been tested with liquid nitrogen at -196°C and is stated to be well suited to LNG duty at around -165°C. In practical engineering terms, this provides a strong reference for cryogenic suitability in marine fuel applications.

DesCargo Deepwell Pump (NDW) is more directly aligned with LNG cargo operations on LNG carriers and bunker vessels. It is designed for loading, unloading and transfer of liquefied gases and is documented for LNG-related service down to -165°C. With capacities up to 1200 m³/h and pressure up to 250 mLC, it addresses substantial marine cargo handling duties where dependable cryogenic performance is required.

For buyers and designers, the practical distinction is straightforward:

• Choose RSL when the primary focus is alternative-fuel service and flexibility across fuel types.

• Choose NDW when the project is centred on LNG cargo transfer for carrier or bunker vessel operation.

Further product details are available for the DesCargo Deepwell Pump (NDW), and related background is available in DESMI’s news article about the DesFuel Deepwell Pump (RSL).

Documentation, Class Requirements and Project Support

Marine LNG projects depend on verified technical documentation. For engineering, procurement and class review processes, the pump supplier must be able to provide clear and traceable information on performance, materials, dimensions and operating limitations. This is especially important in cryogenic systems where temperature, containment and safety functions are closely scrutinised.

Depending on the product and project scope, DESMI can support technical review with documentation such as:

• Technical datasheets

• General arrangement drawings

• Performance curves

• Operation and maintenance manuals

• Material information and traceability data

• Relevant test data for the selected design

Project-specific compliance requirements should always be reviewed against the final vessel design, system arrangement and customer specification. Where relevant, pumps can be supplied in accordance with marine project requirements and supporting documentation packages, subject to model selection and scope. Because LNG pump documentation requirements vary between fuel systems, cargo systems and vessel classes, DESMI works with customers to align the selected pump package with the required approval pathway rather than relying on generic assumptions.

Engineering teams can also use DESMI’s broader digital resources, including product information and technical material across the Marine segment.

Service, Spare Parts and Lifecycle Support for LNG Pump Systems

Selecting the right LNG pump is only the first step. Long-term performance depends on serviceability, access to spare parts and support during commissioning and operation. In mission-critical marine systems, unplanned downtime can affect schedules, fuel availability, cargo operations and operating costs. For that reason, lifecycle support should be considered during the initial specification phase.

DESMI supports customers with technical advice before and after delivery, helping to ensure that the selected cryogenic pump matches the real operating conditions and maintenance strategy. Support can include commissioning assistance, spare parts planning and preventive maintenance recommendations based on the installed system and duty cycle.

• Technical guidance during pump selection and system integration

• Commissioning support for start-up and operational verification

• Spare parts supply for planned maintenance and critical wear components

• Preventive maintenance support to reduce unplanned stoppages

• Long-term service agreements where lifecycle reliability is a priority

• Global support through DESMI’s international sales and service presence

For operators of LNG carriers, bunker vessels and alternative-fuel ships, this support structure helps protect uptime and maintain confidence in everyday operation. It also supports procurement teams seeking a supplier relationship that extends beyond the original equipment delivery.