This International Standard specifies minimum requirements for the material, design, construction and workmanship, manufacturing processes and tests at manufacture of refillable quenched and tempered seamless steel tubes of water capacities from 150 litres up to and including 3000 litres for compressed and liquefied gases exposed to extreme world-wide ambient temperatures (normally between - 50 °C and + 65 °C). This International Standard is applicable to cylinders with a maximum tensile strength Rm of less than 1100 MPa.