Why Are LNG/LPG Carrier Tanks Increasingly Dependent on High-Performance Cryogenic Insulation at -162℃?

From LNG carriers to LPG carriers, this article explains the core logic behind cryogenic tank insulation material selection.

Start with One Number

-162°C。

This is the storage temperature of liquefied natural gas (LNG). Liquefied petroleum gas (LPG) is stored at less extreme temperatures, but it is still a cryogenically liquefied medium.

At this temperature, most materials become brittle or crack, and most conventional insulation systems gradually fail under repeated low-temperature cycling.

Whether it is a membrane tank on an LNG carrier or a self-supporting tank commonly used on LPG and ethylene carriers (IMO Type A/B/C), the insulation system has one critical task: limit external heat ingress, reduce LNG/LPG evaporation losses (BOG), and ensure long-term safe and efficient vessel operation.

The selection of marine cryogenic insulation therefore directly affects the economics and safety of liquefied-gas carriers.

Four Critical Tests for Cryogenic Insulation

For LNG/LPG carrier tanks, LNG terminal storage tanks, LPG tank containers, and other cryogenic equipment, insulation materials must pass four tests:

Thermal Conductivity Must Be Low Enough

The greater the temperature difference, the more demanding the insulation requirements.

At -162°C, the material must maintain extremely low thermal conductivity.

The Structure Must Remain Stable and Prevent Thermal Bridges

The material must not shrink, crack, or deform under cryogenic conditions, as this can create thermal bridges and cause local insulation failure.

Fire Performance Must Meet Requirements

A fire on a vessel can have severe consequences because the space is enclosed.

DNV, ABS, CCS, and other classification societies impose clear and strict fire-performance requirements on LNG/LPG carrier insulation materials.

No Harmful Emissions

The cabin is an enclosed environment, so the insulation must not release VOCs or fibre dust. These substances can endanger crew health, contaminate cargo, and affect measurement accuracy.

Why Are Traditional Insulation Materials Falling Behind?

For EPC contractors and shipyards, conventional insulation solutions are revealing more practical limitations:

Polyurethane Foam (PU):

Its thermal conductivity is relatively high, so a thicker layer is needed to meet performance targets, directly reducing valuable cargo volume. On a vessel, thickness determines capacity, and capacity determines revenue.

Its performance may also deteriorate at extremely low temperatures.

Glass Wool:

It can release fibre dust, making it unsuitable for enclosed cabins with strict requirements for air quality and cargo purity.

Expanded Perlite:

Its relatively high thermal conductivity requires a thicker insulation layer, increasing both space consumption and structural weight.

For shipowners and shipyards, these issues ultimately become direct costs:

Reduced cargo volume, greater structural weight, more frequent maintenance, longer construction cycles, and repeated revisions during classification-society drawing approval.

How Does VPU Pass All Four Requirements?

VPU, a metal-envelope vacuum insulation panel and polyurethane composite module ["VIP + PIR/PU Composite Insulation Panel"], combines a 304 stainless-steel high-barrier vacuum insulation panel (VIP) with polyurethane (PU).

Developed by VacuEco, a Fujian Super Tech company, this new cryogenic insulation module combines extremely low thermal conductivity—approximately 1.2mW/m·K (0.0012W/m·K) after lamination—with modular engineering advantages.

How does VPU address the four challenges above?

Extremely Low Thermal Conductivity Creates Direct Economic Value

The composite thermal conductivity is as low as approximately 1.2mW/m·K (0.0012W/m·K). At the same insulation performance, 40mm of VPU can match 100mm of conventional polyurethane foam.

For the same tank size, this releases more usable cargo volume for the shipowner, directly improving capacity and economics per voyage.

Its performance curve also remains stable under cryogenic conditions without a sudden low-temperature drop.

Stable Stainless-Steel Encapsulation

The 304 stainless-steel high-barrier VIP uses a hot-pressed rigid base shell for deformation and puncture resistance, stable lifecycle performance, and an extremely low corner leakage rate.

PIR Composite System with Better Fire Performance

Compared with conventional polyurethane, PIR offers significantly better fire performance and is better suited to the strict insulation fire-rating requirements of marine applications.

Safe and Environmentally Responsible:

It releases no fibre dust and contains no VOCs, meeting stringent marine environmental and safety requirements while also providing excellent fire and corrosion resistance.

It is suitable for LNG/LPG carriers, gas carriers, and other high-safety applications.

These Are the Issues Customers Care About Most

For shipyards, shipowners, EPC contractors, and other customers, insulation selection involves far more than whether a material can retain cold.
It requires a complete system-level assessment:

Space Determines Capacity:

A thinner insulation layer creates more usable volume and directly improves vessel economics.

Weight Determines Energy Consumption:

A lightweight modular structure helps control vessel weight and reduce fuel consumption.

Compliance Determines Efficiency:

Meeting classification-society fire and safety standards reduces the time spent on drawing review and corrective work.

Reliability Builds Reputation:

Stable long-term cryogenic performance reduces maintenance costs and safety risks during operation.

For membrane or self-supporting tanks on LNG and LPG carriers, as well as onshore LNG terminal tanks and cryogenic pipeline insulation projects, VacuEco provides an integrated solution balancing performance, space, and safety.

-162°C tests more than the material itself.

It tests the technical expertise and engineering experience behind it.

VacuEco is one of the marine insulation solutions currently capable of meeting all four requirements under cryogenic conditions.

Follow VacuEco for more practical information on vacuum insulation technology for LNG and LPG carriers.

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