| abstract |
A one-piece high pressure impact-extruded aluminium gas cylinder has an upstanding neck, in which is formed an auxiliary aperture, particularly intended to receive a check valve which is depressible from its seating for normal operational release of gas from the cylinder. An over pressure relief mechanism is fitted either in the mouth of the cylinder or in a second auxiliary aperture in the neck, preferably diametrically opposite the first auxiliary aperture. Where two auxiliary apertures are provided the fitments therein are preferably axially short to permit a fitment in the mouth to extend down through the neck into the main body of the cylinder. |