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Underwater welding is an important part of any industry where structures are underwater, or shipping is involved. It doesn’t matter whether the structure is a fully submerged pipeline, a partially underwater platform, or a ship. Metal structures need to be repaired, and not all of them can be removed from the water.

Because of this, quality underwater welding technology is vital. Ideally, an underwater weld should be strong enough to permanently become part of the structure, fast to implement, safe and cheap. Unfortunately, most underwater welding techniques can meet only a few of these requirements, and they usually have drawbacks.

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.

Underwater welding can be separated into two basic types - wet and dry. During the process of wet welding, the weld is exposed to the water. This is a fast, inexpensive method that’s often used when a ship or structure can’t be removed from water.

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.

Wet underwater welds need to be repaired more frequently and require routine inspections for damage. This is an alternative to putting a ship into dry dock before scheduled, but in the long run, it’s not always the cheapest.

Dry underwater welding may also be called hyperbaric welding. Usually, it’s done inside a chamber made to isolate the weld from water - this chamber is often pressurized, and contains inert gas. The chamber can be big enough to hold all the equipment, plus the welder, or so small they only surround the weld.

In a variant of dry underwater welding developed by Neptune, the chamber is small, and contains gas pressurized to one unit above the pressure of the water outside. This prevents contamination and allows the chamber to be quickly and easily built, making this one of the cheaper forms of dry welding underwater.

Dry welding is generally considered to be time consuming and expensive, which is why it’s not usually used for quick repairs or fixes that need to be done without disrupting normal routines.

There are a number of risks associated with underwater welding. Shock is a significant danger if the equipment isn’t properly insulated or if the welder doesn’t observe correct procedure. Decompression sickness is another issue that underwater welders should pay attention to - the right precautions will prevent it, but it could be dangerous, or even lethal.

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.

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