In 1932 Russian metallurgist (Konstantin Khrenov) invented underwater welding. Underwater welding is also called hyperbaric welding. It is the process of welding at high pressure in underwater.
When it is used in a dry environment called “hyperbaric welding“. And in the wet environment called “underwater welding“.
Dry welding is used in the preference of welding under wet water when the high-quality weld is required. Due to the increased control in the situations which can be done through the use of before and after weld heat treatment.
Thus, when a very high-quality weld is required, dry hyperbaric welding is used. Research is underway to use dry hyperbaric welding at depth of 1,000 meters (3,300 feet).
In general, assuring the integrity of underwater welds can be difficult. (But it is possible using various non-destructive testing applications). Mainly for wet underwater welds.
There are two methods of underwater welding 1. Wet welding and 2. Dry welding.
Applications of hyperbaric welding.
it is usually used for the repair of ships, offshore oil platforms and pipelines.
There are mainly two types of weldings performed on underwater.
This method is done underwater. This involves the use of designed welding rods and involves the same process used in normal welding.
In wet underwater welding exposes the diver and electrode to the water and surrounding elements. Divers use around 300–400 amps of D.C power to charge their electrode, and they weld using varied forms of arc welding.
Due to hydrogen cracking, the process is usually limited to low carbon equivalent steals, especially in greater depth.
Wet welding is done with the same equipment used for dry welding, but the electrode holders are designed to cool the water and are heavier insulating.
The wet welding process is faster and cheaper.
There is no habitat.
Ease of access to weld spots.
Hyperbaric welding is the process by which a chamber is sealed around the structure that is to be welded. It is filled with a gas (usually a mixture of helium and oxygen, or argon), which then forces water outside the hyperbaric region. This allows for a dry environment in which to perform the weld.
It has a high quality of welding.
It has welder or diver safety.
Dry welding has non-destructive welding.
It has surface monitoring.
To weld properly underwater, a commercial diver uses five main tools: