LESER Update On-board cryogenic applications
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LESER Safety Valves for on-board cryogenic applications

For decades, the international liquefied gas shipping sector has relied on LESER Safety Valves. Apart from specialized LNG vessels designed to carry these energy sources, more and more ships of all types use LNG as fuel.
Over the past 25 years, the liquefied gas sector has become a main pillar of the global energy supply. Driven by the demand for flexible, clean and safe energy, substantial capital has been invested in liquefaction plants, liquefied gas carriers and import terminals. At LESER, this trend arrives mainly in the form of orders from Europe and Germany.
LNG and LPG carriers, whether operating on inland waterways or ocean routes, are often fitted with LESER Safety Valves. While past installations were primarily found on piping, tanks and refrigeration equipment as well as loading and discharging systems, the increasing use of LNG and LPG as ship fuel has expanded the range of applications.
Advanced tankers, cruise ships and ferries often have dual-fuel or pure gas-powered engines, which are likewise often protected by LESER Safety Valves. Today, several hundred vessels are cruising the world’s oceans with LESER valves on board to protect their cryogenic (extremely cold) systems operating at -162 °C. And the number keeps growing. According to the ship classification society DNV Maritime, 87 new ships with LNG propulsion were ordered during the first half of 2025 alone, 81 of them are containerships. An additional 13 LNG bunkering vessels are on order, which are needed to refuel LNG-powered ships.

Technical applications in ship operation

Safety valves are mainly installed in piping sections. Their outlet lines route back to the tanks in a cascading arrangement. Since back pressures are typically encountered in these systems, the valves are equipped with back pressure-compensated stainless steel bellows. The gas load is permanently kept at cryogenic temperatures using multi-stage cooling or reliquefaction systems to keep the medium in liquid state. The safety valves must be able to withstand these temperatures. Their operational integrity must be maintained, and tightness must not be compromised.

Certified by international classification societies

All safety-related components on board, including safety valves, must be approved by a ship classification society (also referred to as "class"). Similar to technical certification experts in land-based installations, class societies monitor compliance with compulsory standards. LESER has been cooperating with all major European, American and Asian classification societies for decades. The class to perform the in-factory approval is chosen by the respective shipowner.
Individual or type approvals by class societies are an indispensable prerequisite for valve delivery to the customer. Despite the unified global rules imposed by the International Maritime Organization (IMO), classes aren’t equal in all aspects. While safety valves for cargo transport are inspected based on the International Gas Carrier Code (IGC-Code), fuel systems are subject to the stipulations of the International Code of Safety for Ships using Gases or Other Low-Flashpoint Fuels (IGF-Code).

Stringent requirements for materials and functional verification

Approval tests apply stringent requirements to both, the material of pressurized parts – especially the body – and the valve’s ability to operate under cryogenic conditions. A valve is not approved for use in on-board liquefied gas applications until it has passed the type test and demonstrated that it will perform reliably under cryogenic operating conditions.
The experience of many years, combined with international collaboration with classification societies and the steady development of valve technology, have enabled LESER to built a solid reputation as a reliable partner to the LNG and LPG shipping segments.