Corrosion is one of the most common and damaging problems in the LNG industry. It doesn’t happen overnight, but once it starts, it never stops. It slowly eats away at valuable components, silently reducing their reliability, safety, and operational lifespan.

Corrosion one of the most damaging problems in the LNG industry

In the LNG sector, the risk is even greater. Spare parts are stored for long periods sometimes for years before they are needed. These parts are often expensive, complex, and critical to the performance of the vessel.

If they fail, the consequences are severe: operational delays, missed deliveries, high replacement costs, and, in the worst cases, vessel downtime.

Many superintendents and technical managers assume that if a spare part is stored indoors or in a crate, it’s safe. Unfortunately, this is not always true.

Humidity, ozone, condensation, and temperature changes can all affect the condition of stored equipment. Even if something looks fine on the outside, corrosion may already have started inside.

What happens when corrosion is not stopped in time?

Let’s look at what happens when corrosion is not stopped in time.

A tail shaft stored in a dry but unsealed warehouse slowly begins to rust due to fluctuations in humidity. No one notices, because the rust is internal. After 3 years, it’s installed on a vessel. A vibration develops. Upon inspection, the shaft is rejected.

A new one must be ordered a process that takes 10 to 12 months. The LNG carrier can’t operate until the new part is delivered. The chartering contract is affected. Revenue is lost. A small preservation failure has now turned into a major operational problem.

This scenario is not unusual. It happens across the industry. Corrosion often starts where it can’t be seen inside bearings, electrical contacts, cooling channels, or shaft surfaces. And once it’s there, it reduces the reliability and safety of the part permanently.

Even short periods of uncontrolled humidity can cause damage. Humidity above 42% is enough to start oxidation on steel. Ozone, which is present in many industrial areas, breaks down rubber and plastic components, leading to cracks, leaks, or loss of insulation.

The solution: stop corrosion before it starts

Corrosion can’t be undone, but it can be prevented.

The key is controlled preservation, high quality mothballing for the LNG industry, a method of storing spare parts in a way that eliminates the environmental factors that cause corrosion. This means removing humidity, keeping out ozone, preventing condensation, and avoiding air stagnation.

At Cocoon Holland, we help LNG operators preserve their strategic spare parts using airtight protective systems that create a dry, stable environment around each component.

Whether the part is stored indoors, outdoors, or in a warehouse, we ensure that the storage conditions remain safe and consistent over time.

How does our Cocoon system work?

Sealing – We apply a multi-layer, airtight skin (the Cocoon) around the part or storage space. This keeps out moisture, dirt, air, and ozone. For large components, we also install spacer hoses to avoid surface contact.
Drying – We use compact, chemical-free air dryers to reduce the humidity inside the sealed space to below 38%. This is well below the threshold at which corrosion can begin. The dryers also filter out ozone, protecting rubber seals and insulation materials.
Monitoring – Each preservation unit is fitted with a data logging system that tracks humidity levels in real time. Our clients receive monthly reports showing that their parts are being stored correctly. This provides both peace of mind and clear proof for audits or insurance.

Why this matters in LNG operations

LNG carriers operate on long-term contracts. Missing a delivery window can result in penalties, lost revenue, or even legal disputes. That’s why spare parts aren’t just stored they are considered part of the operational guarantee.

Many of these parts have long lead times. Propulsion components, electric motors, compressors, spray pumps, turbine rotors they can take 6 to 18 months to replace. This makes preservation not just a technical issue, but a strategic one.

The cost of proper preservation is low compared to the risk of failure. Once a part is corroded or degraded, it can rarely be restored to its original condition. Prevention is the only reliable option.

A long-term spare parts preservation approach

Most LNG vessels are expected to operate for 35 to 40 years. Strategic spare parts must be stored for just as long. That means the preservation solution must not only work today it must continue to protect year after year, even through lay-ups, contract changes, and periods of inactivity.

Cocoon systems are designed for this purpose. They require minimal maintenance (usually once every 5 to 10 years), use no chemicals, and consume very little energy. They are used by companies such as Shell, Total, and NYK to protect high-value components for the full economic life of their fleet.

Corrosion is a constant threat in the LNG sector, especially for spare parts that are not regularly inspected or used.

But it can be stopped if you act before it starts.

By storing parts in a controlled environment or in a LNG depot in Europe with proper sealing, drying, and monitoring, LNG operators can avoid costly failures, preserve the value of their equipment, and protect their ability to deliver on time.

If you’re storing critical LNG spare parts for the long term, ask yourself: