Hyperbaric welding – what is it?

Posted May 18th 2017

Welding is the process of joining together materials, usually metals, but fusing them together through melting the surface points. Two pieces of metal can then be joined to form a single piece. Welding is used for all sorts of reasons from creating metal structures such as bridges and sculptures, to repairing damaged metal structures such as ships.

Hyperbaric welding is a specialist form of welding that requires elevated pressure to work. It is usually performed underwater for this reason. The process can be performed either ‘wet’ or ‘dry’. Wet is when it is performed in the water, and dry is when it takes place in a positive pressure enclosure, or isolation chamber, which gives an increased level of pressure. It is most commonly referred to as hyperbaric welding but when performed in a wet environment it can also be called underwater welding. Hyperbaric welding can be used to repair ships, oil rigs and underwater pipes, and steel is the main material that is used.

Dry hyperbaric welding, as we touched on above, involves the process being carried out in an environment with increased pressure, in a sealed chamber. There will usually be a gas mixture around the chamber. Wet welding is less commonly used and is a skill that less people possess. The welder must also be able to dive, and they are exposed to the risk of electric shock whilst they do this. To prevent this all equipment must be properly insulated and the welding current should be well controlled.

The benefits of this type of welding are that things like oil rigs and ships that are submerged in water can be easily repaired. This makes their maintenance much easier, and more cost effective, as well as enabling the repair to be carried out more quickly than if the structure had to be removed from the water.