ISO 11119-3 specifies requirements for composite gas cylinders up to and including 450 l water capacity, for the storage and conveyance of compressed or liquefied gases with test pressures ranging up to and including 650 bar.

ISO 11119-3 applies to:

1. Fully wrapped composite cylinders with a non-load-sharing metallic or non-metallic liner (i.e. a liner that does not share the load of the overall cylinder design) and a design life from 10 years to non-limited life.
2. Composite cylinders without liners (including cylinders without liners manufactured from two parts joined together) and with a test pressure of less than 60 bar.

The cylinders are constructed:

1. in the form of a disposable mandrel overwrapped with carbon fibre or aramid fibre or glass fibre (or a mixture thereof) in a resin matrix to provide longitudinal and circumferential reinforcement;
2. in the form of two filament wound shells joined together.

ISO 11119-3 does not address the design, fitting and performance of removable protective sleeves.