Nitrogen (N₂) is a versatile gas that is widely used in various industries. Liquid nitrogen is also used in paint stripping, semiconductor cooling, biological sample storage, shrink joints and soil freezing, for example on construction and mining sites.

Nitrogen as a welding gas
In industry, nitrogen gas is used as a shielding gas in oxygen-free processes, such as metalworking, where the presence of oxygen could cause corrosion or other harmful reactions. Nitrogen also acts as a root shielding gas in the welding of high alloy austenitic steels and in inerting processes such as the protection of tanks and reaction vessels. Nitrogen is also used in the homogenisation of metal alloys and in pressure and tooling applications.

In welding, nitrogen is usually used as a minor alloying component in combination with hydrogen (Formier) or argon. As nitrogen is not completely inert, but slightly reactive under welding conditions, it is particularly suitable for welding austenitic nitrogen-alloyed steels and superduplex steels. Nitrogen reactivity is exploited in these materials to prevent nitrogen loss, which maintains the mechanical properties of the steel and improves its corrosion resistance.

In austenitic steels, nitrogen acts as an alloying agent to increase strength and prevent pitting corrosion, thus extending the service life of the material. In the welding of super duplex steels and copper, nitrogen can also be used for root protection as such, protecting the root of the weld from the damaging effects of oxygen.

Available grades:
Industrial nitrogen, food grade nitrogen, high purity nitrogen N50 (5.0), N60 (6.0) and BIP.

Packaging:
Nitrogen is available in cylinders, cylinder packs, liquid nitrogen cans, dewars and mini-containers.

Gases behave differently depending on their quality and state. Always consult the product’s safety data sheet before using the product. A safety data sheet is a document that conveys information about the properties, risks and safe use of a substance or mixture for industrial or professional use.

Risk of suffocation
An increase in the nitrogen concentration in the air you breathe poses a risk of suffocation. Asphyxiation occurs unnoticed and can be fatal. The nitrogen vaporised from the liquid is very cold. Cold nitrogen vapours are heavier than air and can accumulate in drains and basements, causing elevated nitrogen levels in the premises.

First aid
A person suffering from oxygen deficiency should be immediately moved to fresh air. If the victim is having difficulty breathing or is not breathing, administer artificial respiration as quickly as possible and call for help. When rescuing a victim, it is important to remember not to enter an oxygen-deprived area without breathing equipment.

Frostbite injuries
Liquid nitrogen and its vapours are extremely cold and cause
burns to the skin. Touching uninsulated parts of the equipment with bare skin may cause the skin to catch and tear. In the event of an accident, rinse the heavily damaged areas with lukewarm water and seek medical attention.

Unsuitable materials
Certain materials are unsuitable for use at low temperatures because they become brittle and lose their resistance to impact. Materials normally suitable for use at low temperatures are stainless steel, aluminium and their alloys.

Use
– When handling the substance, follow the instructions and safe working practices given
– The gas handler must be properly trained
– Use only carefully checked pressure regulators and other operating equipment suitable for this gas. If in doubt, contact Woikoske.
– Open the valve slowly to avoid pressure shock. About one turn is sufficient to open the cylinder.
– The valve is opened and closed by hand. The use of assistive devices is prohibited!
– The gas cylinder in use must be properly secured.
– Keep the valve outlets clean!
– Close the cylinder valve after each use and when the cylinder is empty.
– Always report damaged valves and cylinders to Woikoske

Transport
– The driver must be aware of the potential dangers of the load and know his duties in the event of accidents and incidents.
– Liquid nitrogen must be carried in open vehicles with the load compartment isolated from the cab
– The transport of gas cylinders shall be carried in an upright position
– The load must be secured
– Cylinders must not be knocked, thrown or dropped from the vehicle platform
– Attention to ADR regulations during transport

Storage
– Observe all legal and local requirements for the storage of cylinders.
– Store cylinders in a well ventilated area
– Cylinders should not be stored in conditions that promote corrosion
– Cylinders are stored upright and secured so that they cannot fall over
– Valve guards must be in place AT ALL TIMES
– Empty and full cylinders to be kept separate