One-way drain valve

The utility model belongs to the technical field of drain valves, and particularly relates to a one-way drain valve. According to the main technical scheme, the device structurally comprises a water inlet cylinder, an outer cylinder mechanism, a protective cover mechanism and an elastic sealing plug mechanism, wherein drain holes are formed in the periphery of the outer cylinder mechanism; wherein the outer cylinder mechanism and the water inlet cylinder are relatively fixed; the protective cover mechanism is fixedly connected with the outer cylinder mechanism; the elastic sealing plug mechanism is composed of a sealing plug body capable of achieving opening and closing sealing of the water inlet cylinder and a deformable soft body structure which is fixed to the upper portion of the sealing plug body and connected with the sealing plug body into a whole. The one-way drain valve with the structure can effectively prevent the function failure of the elastic sealing plug mechanism, and has the characteristics o