Underwater Welding

Underwater welding can be classified according to the type of equipment used and the type of processes followed. The most common underwater welding process is known as MMA - manual metal arc welding which has the advantage of being relatively insensitive to depth.

Cofferdam welding involves the use of a rigid structure to house the welders, which is sealed against the side of the structure to be welded.

Hyperbaric welding is another type of underwater welding technique in which an enclosure is sealed around the structure to be welded, and is filled with a helium gas. This welding technique is commonly combined with manual metal arc welding for effecting high integrity deep-water welds.

A recent technology developed by Neptune Marine is the NEPSYS Dry Underwater Welding system. This dry underwater welding system dramatically improves conventional offshore oil and gas and marine maintenance practices.

Neptune Marine developed the system due to the fact that existing under water welding technologies provided only temporary solutions that often required reworking. In the case of hyperbaric welding or dry docking, there was a significant operational impact and substantial costs involved.

Neptune Marine with the Nepsys underwater dry weld system can now deliver a comparatively low cost underwater welding system that applies a permanent weld equal to dry weld standards.

Some of the Key benefits of this new technology include: Superior weld quality compared to conventional underwater welding technology, lower direct costs than hyperbaric, cofferdam and dry dock welding methods, Elimination of indirect costs associated with transit, rapid response time and is suitable for emergency marine repairs.

Underwater welding techniques can be dangerous, even fatal if proper procedures and equipment is not used. An underwater welder faces the potential risk from electric shocks and from nitrogen introduced into the bloodstream during exposure to air at increased pressure. Underwater welding safety measures include emergency air or gas supply, stand-by divers, and decompression chambers to avoid decompression sickness following rapid surfacing after saturation diving.

Nepsys Dry Underwater Welding Videos
Video and animation of the how The NEPSYS Dry Underwater Welding system works - see it in action!