From the word Underwater welding,this implies that the welding operation is carried out or performed under the water, while the welder(is a skilled person who performed the operation) is submerged under the water, often at elevated barometric pressures.
Although in most african countries this course is not widely taught except with some few exception This specialization require specialized skills and training that are taught in advance Technical Institutions where their maritime industry has already reached advance stage,Maritime experts recognized the importance of this course,because of the adverse conditions and inherent dangers associated with underwater welding (also known as wet welding) divers must be trained to an exceptionally rigorous standard with highly specialized instruction.
There are two methods of Underwater welding:
Wet welding & Dry welding
Welding underwater can be achieved by two methods: wet welding & dry welding. Wet welding entails the diver to perform the weld directly in the water. It involves using a specially designed welding rod, and employs a similar process used in ordinary welding.
Here are advantages to wet welding:
–Cheap and fast
–high tensile strength
–ease of access to weld spot
–No habitat
–No construction
Dry Under water Welding
Another method of welding underwater is hyperbaric welding or dry welding. Hyperbaric welding is the process by which a chamber is sealed around the structure that is to be welded. It is then filled with a gas (typically mixture of helium and oxygen, or argon), which then forces the water outside of the hyperbaric sphere. This is usually done in a dry environment in which to perform the weld.
Here are some advantages to dry welding:
—welder / diver safety
—higher weld quality
—surface monitoring
—Non-destructive testing
A graduate student of under water course may earn an underwater welding certification, under AWS standards D3.6. The underwater welding qualification meets a strict standard and is only achieved by the most dedicated students. It requires successful completion of the practical portion of both the Top-side and the Underwater Welding course and recognizes Underwater Welding Qualifications for Class C fillet weld to AWS D3.6M.
Graduates who are proficient in underwater course could work in any oil field,oil rig,vessel ,salvage operation , pipeline construction and repair, rigging, the operations of underwater tools (jack-hammers, hydraulic drills and chainsaws).etc
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