A diving cylinder, also known as a scuba tank, contains the pressurized breathing gas for scuba diving. Divers can choose various types of tanks to fit their diving needs. Tanks should be well-maintained and might require formal inspections.
The tanks are frequently made of either aluminum or steel, and each material offers advantages and disadvantages. Aluminum tanks typically are less expensive than steel, although they might not last as long. In addition, aluminum weighs less than steel, and the lighter tanks can be easier for divers who are less strong. Steel tanks might be more affected by corrosion, especially from sea water; these tanks are often painted or coated to protect them.
Another important piece of a diving cylinder is the valve. A valve connects the tank to the diver’s regulator, or breathing apparatus, and the regular and valve fittings must be compatible. The two most common types of valves are the yoke and din.
A diving cylinder can be designed to mount of the back of the diver’s buoyancy control device (BCD) or on the sides. The back mount style is most common. Side mount styles offer an advantage in that they might allow the diver to move through the water more easily.
Diving tanks are assigned pressure ratings. A rating indicates the amount of gas that the diving cylinder can hold. Pressure ratings can also relate to the size of the tank and to the time that a diver might expect to use the tank during a dive.
Tanks also can be categorized by the type of gas used. Compressed air is commonly used, but for different types of diving, other gases, such as nitrox, can be used. Labels are affixed to the tanks so that the types of gases are easily identifiable.
Diving cylinders come in a variety of dimensions. Frequently, they will be 17-30 inches (43.2-76.2 cm) high and 6.9-8 inches (17.5-20.3 cm) in diameter. Divers can choose cylinders that fit their body size and diving style. For example, a small person might find a smaller cylinder size to be more comfortable. Someone who is planning longer dives might prefer a larger tank.
Tanks are critical components of scuba diving equipment. They should be well maintained to ensure the safety of divers and operators who might fill or otherwise handle them. Many nations require inspections every year or every few years.