This European Standard specifies seamless and welded steel or seamless aluminium alloy cylinders intended for the transport of acetylene in cylinders of water capacity up to 150 l and specifies the requirements for the periodic inspection and maintenance of acetylene cylinders, regardless of the method of manufacture of the shell. This European Standard also applies to solvent free acetylene cylinders. This European Standard also specifies a procedure to qualify existing gas cylinders for free movement between member states of the European Union (see annex A).