If you thought your job is tough, think again. Underwater welding is one of the toughest occupations in the world. Under the enormous water pressure, visuals blocked by water bubbles, bringing two pieces of metal together to repair pipelines, oil rigs, and nuclear facilities is no joke.
Welding at high pressures is termed as Hyperbaric Welding. It is done either in specially constructed chambers with positive pressures, called dry welding, or out open in the water, called wet welding. In the dry welding, the hyperbaric chambers keep the water out keeping the cabins pressurized to minimize pressure sickness. Fans are installed in the chamber, that change exhausted air with fresh air consistently.
In the dry underwater welding, the hyperbaric chambers keep the water out keeping the cabins pressurized to minimize pressure sickness. Fans are installed in the chamber, that change exhausted air with fresh air consistently.
The wet welding technique is used as a temporary solution in emergency situations. The wet welds can cool down too quickly by the water thus increasing the chance of cracking. Mostly done in hard to access areas, wet welding requires working in severely dark and cold environments with minimal visibility.
Just like the conventional welding, underwater welding also uses electricity as the energy source. The technique most commonly used under water is the stick welding that uses an electric arc. In the case of wet welding, the flux on the outside of the rod creates bubbles when it evaporates. These bubbles form a gaseous layer over the joint protecting it from oxidizing agents.
Electricity is not the only hazard to a diver welding underwater. One of the most dangerous of all hazards is the differential pressure. The differential pressures called Delta P (?P) occur when two water bodies with different water level intersect. The water level difference makes the water rush from higher to the lower level with tremendous force. The pressure difference can go up to hundreds of pounds per square inch, creating an incredibly high risk of drowning. Safety procedures if not followed accurately can cause fatal accidents to even the most experienced of divers.
These welders are heroes that dive deep into the waters to maintain systems that almost all humans are relying on. It is not just a tough job; it is a necessity for so many of the important world systems. Until we can develop robots that will be able to perform these tasks as well as the humans, the world will continue to rely on the mentally and physically challenging job of an underwater welder.