Scuba tanks are a basic component of any scuba diver's kit. While they contain no air, they do contain a large volume of free gas, which is generally greater than the amount of water they can hold. The tank size will vary depending on what type of diving you do. You'll need to select the right tank based upon the water type you intend to use. Below are the main types, as well as their sizes.
scuba tanks contain no air
The standard aluminum 80 can holds 77 feet3 air. Trimix is a type of dive fuel that has a lower capacity than air. It can hold between ten and twenty percent more. A higher maximum service pressure does not necessarily mean more air. However, manufacturers are known to overstate the capacity of their tanks. Hence, you should compare the capacity of each cylinder against the actual volume of air in it.
They have more gas than water and contain more free gas.
Technical divers use mixed gases differently to recreational divers. Their true air and Trimix capacities, however, are lower than their actual water capacities. For example, Helium is more compressible than air so their true air and trimix capacities are lower than their water capacities. Heliair 10/50 is true to its air capacity at 216 ft3 while Double HP117 has an air volume equivalent to 235 ft3. To determine the correct mixed gas capacity, use the Z Factors for SCUBA tables.
They can be made from steel or aluminum
If you are faced with the choice between an aluminum and a steel scuba tank, make sure to consider what is best for your needs. Steel tanks can withstand deeper dives and are more durable. This durability comes at an expense. Aluminum tanks are more susceptible to structural fractures and can prove dangerous. A steel tank costs more that an aluminum one. But aluminum tanks are now the industry standard.
They are available at different sizes
Two materials are used to make scuba tanks: aluminum and steel. Steel tanks are lighter, more durable and heavier than aluminum tanks. However, they tend to be heavier. An aluminum tank is better if you are planning to do a lot more diving and bring a weight belt. You should know that aluminum tanks can be heavier than steel tanks and are therefore lighter than steel tanks. Steel tanks are ideal for drysuit diving or local scuba diving.
They should be checked regularly
There are many ways to inspect your scuba tank. Hydrostatic testing usually is done below the tank's neck. A visual inspection can also help you find corrosion or contamination. Tumbling is another way of checking the tank's condition. Tumbling involves filling it with media and spinning it for a certain period of time to remove dirt and other contaminants. If the tank sounds rattly, it may mean it needs to be cleaned.