Provides minimum requirements for the material, design, construction and workmanship, manufacturing processes and tests at manufacture of refillable transportable seamless steel gas cylinders of water capacities from 0,5 litres up to and including 150 litres for compressed, liquefied and dissolved gases. Applicable to cylinders with a value of R[m] max. >= 1 100 MPa. Does not cover cylinders with diameters > 140 mm where either R[m] max. > 1 300 MPa or the design wall thickness > 12 mm. Also does not cover cylinders with diameters <= 140 mm where either R[m] max. >= 1 400 MPa or the design wall thickness >= 6 mm, because beyond these limits additional requirements could possibly apply.