Scuba tanks should be a part of every diver's kit. They do not contain air but they do have large amounts of free gas. Tank sizes vary according to the type of diving you'll be doing, and you'll want to choose the right one based on the type of water you plan to go in. Below is a list of the most common scuba tanks, along with their sizes.
scuba tanks contain no air
The standard aluminum 80 cylinder has a capacity of 77 ft3 of air. Trimix, a dive gas, is 10-20% smaller than air. A higher maximum operating pressure doesn’t necessarily mean that there is more air. However, manufacturers tend to exaggerate the tanks' capacities. You should therefore compare the capacity of each cylindrical against the actual volume.
They contain a volume of free gas greater than their water capacity
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's true air capacity is 216ft3 while double HP117 cylinders hold a true volume air volume at 235ft3. You can use the Z Factors of SCUBA tables to determine the correct mixed gases capacity.
They can be made of aluminum or steel
You should consider the divers' needs when choosing between an aluminium or steel scuba tanks. Steel tanks are more durable, and can withstand deeper diving. This durability comes at a price. Aluminum tanks can easily develop structural fractures which can lead to serious injury. A steel tank can also be more expensive than an aluminium one. But aluminum tanks are now the industry standard.
They are available in different sizes
Two materials are used to make scuba tanks: aluminum and steel. Steel tanks tend to be lighter and more durable than aluminum, but they are heavier. Aluminum tanks are better for those who plan on diving a lot and have a weight belt. Aluminum tanks are lighter than steel tanks. You will need to consider your weight requirements when purchasing an aluminum tank. Steel tanks can be used for local and drysuit diving.
They must be inspected regularly
There are many options for checking your scuba diving tank. Hydrostatic testing is usually stamped into the metal beneath the neck of the tank. Visual inspections can be used to help detect corrosion or contamination. Tumbling can be used to test the condition of your tank. Tumbling involves filling your tank with media, and then spinning it for a period of time to remove any dirt or other contaminants. If the tank's sound is unusual, it might be an indication that it needs to get cleaned.