Your Scuba Tank
A cylinder (more commonly called “scuba tank”) holds compressed breathing air that you use during the dive. Modern scuba tanks are made from aluminum alloy or steel alloy and are rated to hold pressures as high as 200 bar/3000 psi. Your dive regulator attaches to the cylinder valve.
Also known as : tank, scuba bottle, dive tank, scuba cylinder, high pressure cylinder
Valve – The valve controls the flow of air by simply turning the handwheel open or closed.
Burst disk – Part of the valve, this safety device releases the air from the cylinder if it accidentally gets too much pressure in it.
Inspection decal – For safety, scuba tanks must be inspected annually. This decal shows dive shop employees filling it that it is within the inspection cycle and may be filled. Your PADI Dive Shop or Resort can perform these inspections.
Tank boot – Allows cylinders with rounded bottoms (primarily steel) to stand during storage. Also helps protect surfaces from damage by cylinders.
DIN or Yoke – Regulators and tank valves are either DIN (regulator screws into valve) or yoke (regulator bracket slides down over valve). You’ll choose this based on which is most common where you dive.
Steel or aluminum – Both cylinder materials are well proven and reliable. Steel cylinders tend to be more compact for a given capacity. Aluminum cylinders tend to resist corrosion better, though they do need maintenance.
Size and capacity – You can get different sized scuba tanks, and the capacity also varies with the pressure rating. Generally, you want the highest capacity you can wear and transport comfortably.
Enriched air – Enriched air is air with extra oxygen to reduce the nitrogen. This gives you longer dive times in some situations, but your tank needs special markings and preparation. Learn all about it in the PADI Enriched Air Nitrox Specialty Course.
How to choose a cylinder
Your primary considerations in choosing a scuba tank are size, capacity and buoyancy.
- You generally want the largest tank you can wear comfortably and carry. But, if you’re a smaller person, a smaller tank may provide ample air to make the same length dive as a larger person with a larger tank.
- Diving with enriched air nitrox is increasingly common and has a lot of advantages. Ask your PADI Dive Shop or Resort about your options for this in your area.
- Obviously, your regulator [link to 220.127.116.11] and tank should both be DIN or yoke system.
- If you’re going to dive alot locally, a scuba tank is a good investment. If most of your diving involves air travel, however, you may not need one at all (you rent cylinders at your destination).