Cylinder (Scuba Tank)
Definition
A scuba cylinder is a high-pressure tank used to store compressed breathing gas for underwater use.
More on Cylinder (Scuba Tank)
Scuba cylinders, also known as tanks, are essential components of a diver’s breathing system. They store compressed air or breathing gas blends like nitrox or trimix at high pressure, typically between 200 to 300 bar (2900–4350 psi). Cylinders are made from either aluminum or steel and come in various sizes, commonly 80 cubic feet (11.1L) for recreational diving. Each cylinder includes a valve (DIN or yoke), hydrostatic test markings, and working pressure ratings. Proper cylinder care, including visual inspections and hydro tests, is critical for dive safety.
Frequently Asked Questions
Most scuba tanks are made from aluminum or steel. Steel tanks are heavier and negatively buoyant, while aluminum tanks are lighter and tend to become positively buoyant near empty.
Typical working pressures range from 200 to 300 bar (or 3000 to 4350 psi), depending on the tank type and rating.
Cylinders require a hydrostatic test every 5 years and a visual inspection annually in most countries.
DIN valves screw into the regulator and offer better sealing for high-pressure use. Yoke (A-clamp) valves clamp around the valve and are more common in recreational diving.
Due to air travel restrictions, most divers rent tanks at their destination. Empty cylinders must be visibly marked and valve-opened for air transport.