Nickel – a VIP solution…

Vacuum insulated piping (VIP) makes it possible to transport liquefied gases at temperatures well below 0 °C to facilitate the energy transition

VIP and nickel

Climate change is making us strive to become less dependent on fossil fuels. Non-carbon dioxide emitting fuels such as hydrogen and ammonia provide alternatives. And as we transition towards non-fossil fuels, liquefied natural gas has proven to be a working intermediate alternative to oil as an  energy source to produce electricity or heating.

The production, transportation and use of these alternative energy carriers however requires liquefying them at some point in the process.

In the case of liquefied natural gas (LNG), this happens at very low temperatures. Care must be taken to ensure that the cooled and liquefied gases stay liquid as long required to store and supply them. For this to work requires proper insulation of the liquefied gases from the environment.

This is where nickel comes into the picture. Nickel-containing stainless steels have many attractive properties. Above all, they are ductile and resilient, even at low temperatures, which makes them the materials of choice to efficiently transport liquefied gases through piping networks.

LNG storage and bunkering making use of VIP (© Cryospain)
LNG storage and bunkering making use of VIP (© Cryospain)

How does vacuum insulation work?

Think of a pipe-in-pipe layout that carries the liquefied gas in the inner pipe. Vacuum insulation between the two pipes prevents any loss of heat through conduction because the air (which is a conductor) is removed from the space between inner and outer pipe. Translated into industrial applications, nickel containing stainless steels are used for both pipes as well as for the necessary spacers, valves and compensation bellows, which allow the cooling equipment to operate across a range of temperatures.

VIP can be used to transfer liquid hydrogen, argon, nitrogen, carboin dioxide, oxygen, helium and LNG.

Benefits of vacuum insulated piping using nickel-containing stainless steel

The benefits of VIP (as opposed to traditional insulation using foam for example) are many.

Firstly, there is the cooling efficiency, which keeps operating costs lower than those of traditional insulating methods.

Secondly, vacuum insulated transfer lines take up less space than conventional insulation piping. The double-wall system with vacuum in between offers an insulation value that is so high that it can only be matched by applying many layers of foam-like materials, thus increasing the system’s outer diameter.

Also, when safety requires a double-containment system, the outer pipe provides just that. The double-containment also mitigates the risk if the inner tube was to leak. Foam insulated transfer pipes are unable to offer such a safety feature and require a concrete safety trench, which increases cost.

Traditional insulation solutions require the piping to be mounted on-site and special care is needed to keep the insulation layer intact.  In contrast, double-walled stainless steel VIP can be pre-assembled in the factory and can be installed on-site in half the time that would be required for pipes with traditional insulation.  And whereas foam-like insulation has a life span of only ten years, vacuum insulated piping using stainless steel is expected to last for at least 20 years.

Such VIP systems can for example connect an onshore LNG storage plant with the LNG bunkering port’s loading and unloading jetty. The technology also enables gasification of liquefied gas to be limited during transfer thanks to the high insulation efficiency.

Arslo Stainless Steel Double-wall Insulated Water Bottle
Arslo Stainless Steel Double-wall Insulated Water Bottle

Nickel… a VIP solution… how “cool” is that?

The use of nickel-containing stainless steels for vacuum insulation is not limited to industrial solutions. In fact, drinking water bottles make use of the same principle. Vacuum-sealed bottles are double-walled too (whereas double-walled doesn’t necessarily mean “vacuum sealed”).

A stainless steel bottle that has been "vacuum-sealed" has two walls with a gap in between, which, due to the absence of any molecules doesn’t transfer heat. A gap as small as 1 mm for the air can insulate the food or drink inside your container!

This article was first published in our Nickel Magazine VOL 38-1, in April 2023.

Top picture: Stainless pipe-in-pipe factory assembly ©Schwanner GmbH