Tanks for SCUBA Diving

Scuba tanks come in a number of sizes with different valves and different gas contents. When selecting the type of tank required, you need to assess what the tank is going to be used for and who will be using it. This will make sure the diver gains optimum performance from the selected tank.

  1. Materials

    • Scuba tanks are made from either steel or aluminum. Steel tanks are generally lighter than aluminum ones of the same gas capacity and have a longer life span when cared for properly. Aluminum tanks are considerably cheaper than steel tanks but not as durable and tolerant to heat. Currently, however, while steel tanks are the preferred choice of experienced divers, aluminum tanks are used by a majority of dive operations worldwide.

    Valves

    • The two main types of valves on a scuba tank are the international yoke valve or a DIN valve. The yoke valve is a valve fitted with an o-ring onto which a regulator is attached. A DIN valve is a threaded valve into which a regulator screws. The DIN valve is preferred by experienced divers who have DIN regulators as it can work with higher tank pressures. The yoke valve, however, is more widely used. Newer scuba tanks can come with either a choice of both valves, or a yoke adaptor for a DIN tank that is applied with an allen key. This tank is a 200 bar tank rather than the higher pressure 300 bar DIN tank used normally. Thus it is possible to cater to divers using either type of regulator.

    Size and configuration

    • Diver tanks come in a variety of sizes ranging from the small pony bottle to the larger 15 liter cylinders. What the diver is using the tank for is a major consideration in selection. A person with greater air consumption might look at taking a 15 liter tank over a normal 12 liter tank to compensate for the fact that he uses the air faster. A 6 liter cylinder might be better for a child rather than the larger cylinders favored by adults. Technical divers have the most to consider in cylinder size and configuration as they will be down for longer, with decompression stops. For these purposes, there are twin tank configurations and larger pony bottles used for technical diving.

    Content

    • What the tank contains is important. Cylinders that are going to contain enriched air nitrox or pure oxygen need to be oxygen cleaned to remove any substance that could ignite, such as oil grease. This reduces the possibility of explosions with the presence of higher levels of oxygen, which can support combustion and cause other materials to burn. They need to be clearly marked with green and gold labels (and any other markings that local laws require) declaring the contents, and their contents verified before every use.