A threaded flange for a flexible tank that has a base, an upstanding passage, an upstanding support assembly and a grasping member. The base has an upper surface, and a lower surface opposite the upper surface, and an outer perimeter and an inner opening. The upstanding passage extends upwardly away from the upper surface of the base and has a lower end and an upper end, an inner surface and an outer surface, with the inner surface being threaded. The upstanding support assembly comprises a plurality of ribs extending outwardly from the outer surface of the upstanding passage and upwardly from the upper surface of the base. The grasping member is accessible from the lower surface of the base, wherein the grasping member is accessible by and structurally configured for coupling with a tool.