Removable clamp structure for tank sections which at times block said removal

In a tank closure system, the combination comprising

• (a) complementary sections of a tank adapted to contain pressurized fluid, said sections having annular flanges which are subject to relative separation as the tank sections relatively separate due to said fluid pressurization,
• (b) said flanges respectively having oppositely facing annular surfaces which extend in relatively divergent relation away from the tank interior, and
• (c) clamp means assembled onto said flanges and having channel shape with webs extending in complementary relation to said divergent surfaces to engage the flanges and block said relative separation of the flanges at which time removal of the clamp means off the flanges is also blocked by said divergent surfaces,
• (d) the webs having relatively divergent surfaces complementary to said flange divergent surfaces to engage same in response to said relative separation of the flanges, the webs being vertically spaced apart, the upper web divergent surface extending radially outwardly and upwardly relative to a horizontal plane, and the lower web divergent surface extending radially outwardly and downwardly relative to said horizontal plane,
• (e) there being terminal flanges respectively integral with the webs to stiffen the webs, said terminal flanges extending generally vertically proximate said tank sections.