With regard to the correspondence in circulation originating from the H.S.A. , I would like to point out that the cylinder in question is a single valve cylinder, which in most cases are used only in a cylinder exchange system(i.e. filled by bulk gas suppliers only) and are filled to 80% capacity by measuring the amount of gas by weight or volume. The multi valve forklift truck cylinders that we supply are different in that they have a fixed maximum liquid level gauge(vent valve), where 80% fill is invariably definitively indicated when a steady white mist is emitted from this valve which is open during filling, ensuring no more than 80% fill.