Underwater welding is an important part of any industry that involves shipping or structures that are entirely or partially under water. From pipelines, to platforms to ships, metal structures must be repaired, and in many cases can’t be removed from the water.
Developing good technology for underwater welding is important. Ideally, an underwater weld ought to be strong enough to permanently be part of the structure. It should also be quick and cheap to implement, without being dangerous – unfortunately, no method can meet all of these standards.
Underwater welding has a number of risks, and must be done by specialists trained to use the equipment and take the appropriate precautions. Underwater welders may be employed by oil and gas industries, shipping companies or even the military.
Wet and dry underwater welding are the two basic types. Wet welding is when the weld is exposed to the water while being created. It’s a speedy, inexpensive welding method, and it’s commonly used on underwater structures, or when a ship can’t be put into dry dock.
The down side of wet underwater welding is that it’s not as structurally stable as a dry weld. Water can interrupt the welding process, cause hot and cold spots, or even explosive pockets of hydrogen and oxygen. Wet welds are almost always temporary, and don’t provide as great percentages of elongation as dry welds.
This means that a wet underwater weld tends to need repair often, and must be inspected regularly for damage. It’s an alternative to prematurely putting a ship in dry dock, but not always the cheapest one in the long run.
Dry underwater welding is often referred to as hyperbaric welding. It’s usually carried out in a chamber built to isolate the weld from the water outside. This chamber may be pressurized and contain inert gas. Chambers vary from large enough to hold the welder and all his or her equipment to small enough to surround only the weld.
One variant of underwater welding developed by Neptune uses a very small chamber fulled with gas pressurized to one unit above the outside water pressure. This helps prevent contamination and lets the chamber be built quickly and easily. This is one of the least expensive forms of dry underwater welding.
Dry underwater welding is usually thought of as time consuming and expensive, so it’s not often used for repairs that must be done quickly. It can be disruptive to ordinary routines, because it’s often complicated, but it produces a much stronger weld.
Underwater welding has a number of risks associated with it. One of them is shock from improperly insulated or used equipment. Another is decompression sickness, a problem that can be avoided with the right precautions, but which can be lethal if they’re not observed.
Every kind of welding has its own problems and benefits. Picking the right method for your application requires knowing your available resources and your needs. Be sure to investigate all options, even if they’re new to the market, when you look for the perfect underwater welding solution.