摘要 |
An internally pressurized fluid container has a dome-shaped inwardly concave closure element 16 circumferentially joined to one end of the tubular container side wall. The closure element is deep drawn of tempered steel, with a circular central area 34 spaced from an annular outer area 24 by an annular intermediate area 26 traversed by radially extending Lüders Lines 30. A tab member is located in the central area 34. The tab member is partially circumscribed by a single weakened circular line 36 of reduced material thickness, with the ends of the line being separated by a connecting area 38 of substantially undisturbed material thickness and strength. An increase in fluid pressure above a prescribed level causes a fracture of the closure element 16 along the weakened line of reduced material thickness. <IMAGE> |