ISO 18172-2:2007 specifies minimum requirements concerning material, design, construction and workmanship, manufacturing processes and testing of refillable transportable welded stainless steel gas cylinders, of water capacities from 0,5 l up to and including 150 l, for compressed and liquefied gases. ISO 18172-2:2007 is applicable only to cylinders manufactured from stainless steels with a maximum tensile strength of less than 1 100 MPa and a test pressure above 6 MPa (60 bar).