Vacuum breaker valve

A vacuum breaker valve, including:

• a barrel member, including an inlet end, an outlet end and at least one air passage communicating with the outlet end, an inner wall of the barrel member having a shoulder portion;
• a biasing assembly, abutting against the barrel member;
• a water stop gasket, having at least one water flowing hole, the water stop gasket disposed in the barrel member and abutting against the biasing assembly, a circumference of the water stop gasket having a water stop portion which is deformable, the water stop portion corresponding to the at least one air passage;
• a plate, located between the inlet end and the water stop gasket, having at least one through hole communicating with the inlet end, a circumference of the plate protruding radially outward to form an engaging flange structure and having a material-reduced structure near the engaging flange structure, the material-reduced structure allowing the engaging flange structure to elastically deform to be received in the barrel member so that the engaging flange structure is blockable, in a direction toward the inlet end, by the shoulder portion;
• wherein the biasing assembly normally drives the water stop portion of the water stop gasket apart from the at least one air passage to keep the at least one air passage non-closed.