Retaining tank for retaining e.g. rain water, has oblong sealing blades releasing median opening in maximum opening position and sealing periphery of median opening without modifying center of gravity in minimum opening position

摘要

The tank has a set of oblong sealing blades (8) distributed around a median opening. Front and back faces of the blades are provided with a front eyelet (34) and a rear eyelet, respectively. The eyelets are articulated in an articulation drilling and a radial groove (9) associated with an actuation ring (6), respectively such that the blades move between maximum and minimum opening positions according to a level of effluents in the tank. The blades release the opening in the maximum position and seal a periphery of the opening without modifying a center of gravity in the minimum position.