BALL TYPE FIRE HYDRANT DEVICE

PROBLEM TO BE SOLVED: To provide a mechanism for preventing the injection of the high pressure fluid from a water conduit passage side to a water discharge passage side when a fire hydrant is opened at a low degree of opening in the case of inspecting the fire hydrant. SOLUTION: A ball type fire hydrant BV, in which a water conduit passage 7 and a water discharge passage 8 are cut from each other or connected to each other inside of a valve casing 4 in response to the turning angle of a spherical valve element 1, the spherical valve element 1 is provided with a primary side spherical surface part 15 to be engaged with a primary side valve seat 9 at one side of one surface S having a through-hole 2 and an axis of a turning shaft 3 in common, and provided with a secondary side spherical surface part 16 to be engaged with a secondary side valve seat 10 at the one end thereof. The spherical valve element 1 is also provided with a secondary side outflow passage forming means 17 for securing the water cutoff condition between the primary side valve seat 9 and the primary side spherical surface part 15 in the case of fully closing the ball type fire plug BV and for forming an opening area of the fluid passage to be formed in the secondary side larger than the opening area of the fluid passage formed in a primary side in the case of opening the fire plug at a low degree of opening.