METHOD FOR MANUFACTURE OF METAL GAS BALLOON CASING Russian patent published in 1997 - IPC

FIELD: mechanical engineering, in particular, production of pressure vessels from low-carbon steel. SUBSTANCE: method involves manufacturing two caps from measured billets of predetermined thickness and diameter by stretching without thinning; providing thermochemical treatment. Both caps are made from single measured billet. In the process of manufacture, one of caps may be provided with neck formed by rotational reduction and supporting member, such as shoe, is welded to cap bottom. Bottom of other cap may be provided with opening by die punching. Vent coupling may be mounted in opening by welding and other members, such as collar or handle, may be welded on outside surface. Bottoms produced are connected to assemble balloon by annular butt-weld joint. Balloon casing is subjected to thermal treatment for normalization at temperature of 850-900 C and held for 3-20 min. EFFECT: increased efficiency and improved quality of balloons. 2 dwg