A system for closing holes (20), said system comprising: a hole (28) for establishing a communication between an inner volume (32) that can receive a fluid substance and an outside environment (30), the hole (28) having a coupling surface oriented laterally inwards (34)； a valve (24) that includes an elastic flexible head (36) extending through the hole (28), the head (36) having: an inner side (40) oriented towards the inner volume (32)； an outer side (38) oriented towards the outside environment (30)； at least one self-sealing groove (50) through the head (36)； being open portions (51) facing along the groove (50) to define a normally closed hole in an unrestricted condition where the open portions (51) can move in a first direction towards the volume indoor (32) taking an open hole configuration and in a second direction towards the outside environment (30) taking an open hole configuration； and a peripheral surface oriented laterally outwardly (54) compressed laterally inwardly by its coupling against the coupling surface (34) to thereby exert a closing force on said self-sealing groove (50) to increase the resistance to the opening of the orifice normally closed at least in the second direction when the valve head (36) is subjected to a pressure differential acting through the valve head (36)； and characterized by an annular flange (62) located to extend over at least a portion of the outer side (38) of said valve head (36) to limit the movement of the portions that can be opened (51) in the second direction.Un sistema para cerrar orificios (20), comprendiendo dicho sistema: un orificio (28) para establecer una comunicación entre un volumen interior (32) que puede recibir una sustancia fluida y un ambiente exterior (30), teniendo el orificio (28) una superficie de acoplamiento orientada lateralmente hacia el interior (34)； una válvula (24) que incluye un cabezal flexible elástico (36) que se extiende a través del orificio (28), teniendo el cabezal (36): un lado
