Patent ID: 8608013

Claim:
A gas cylinder comprising a cylinder body internally defining a gas storing space that is closable by a closure valve, in which said cylinder body comprises: a tubular wall defining said gas storing space; a bottom wall connected to a tubular wall lower end and defining the gas storing space on a cylinder lower side; an upper wall connected to a tubular wall upper end and defining the gas storing space on a cylinder upper side opposite the lower side; wherein the tubular wall comprises at least a first tubular portion that is enlarged, and at least a second tubular portion that is adjacent and narrowed relative to the first tubular portion, wherein the tubular wall has a substantially constant thickness, and wherein the narrowed portion forms a substantially cylindrical circular central ring having a constant diameter along the longitudinal axis, and two transition side rings connect the central ring to the adjacent enlarged tubular portions, wherein the side rings form circumferential steps.