Patent ID: 8453868

Claim:
Gas cylinder ( 1 ) internally defining a gas storage space ( 2 ) able to be closed by a stop valve ( 3 ), wherein said cylinder ( 1 ) comprises: a rigid wall ( 4 ) made from composite material having a reinforcing layer ( 5 ) containing reinforcing fibres and an inner surface ( 6 ) that defines an inner space ( 7 ) accessible through an access opening ( 8 ) formed in the rigid wall ( 4 ), a tubular mouth ( 9 ) connected to the access opening ( 8 ) of the rigid wall ( 4 ) and configured to receive the stop valve ( 3 ) in communication with the gas storage space ( 2 ), a flexible sealing wall ( 13 ) arranged in the inner space ( 7 ) and connected to the rigid wall ( 4 ) only through the mouth ( 9 ), said flexible sealing wall ( 13 ) internally defining said gas storage space ( 2 ) and being suitable for adhering in pressing contact against the inner surface ( 6 ) of the rigid wall ( 4 ), wherein the rigid wall ( 4 ) is permeable to air so as to allow a complete expansion of the flexible wall ( 13 ) in the inner space ( 7 ) and the inner surface ( 6 ) is formed from a sliding layer ( 14 ) of the rigid wall ( 4 ) different from the reinforcing layer ( 5 ) and that allows sliding in pressing contact between the flexible sealing wall ( 13 ) and the rigid wall ( 4 ).