| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and simple exhaust valve capable of exhausting a small amount of air accumulated in a pipe to surely prevent backflow even when a minute negative pressure state generates in the pipe in being submerged, exerting a backflow preventing function for a long period without affected by foreign matters in a fluid, and without performing replacement and maintenance of internal components, and reducing the number of components by simplifying an internal structure, and to provide a fire hydrant with the exhaust valve.SOLUTION: A flow valve element 4 vertically movably disposed in a cylindrical body 2, closes a communication part 35 at its lower face 4a through a gasket 33 in descending, and closes a small air hole 11 by being kept into contact with a valve seat 10 for the small air hole, of the body 2 at its upper face 4b, in ascending. A projecting portion 22 having a communication path 23 communicated with the small air hole 11, is disposed in a projecting manner in an air region portion 20 formed between an inner peripheral face 3a of a cap 3 and an upper portion of the body 2, an exhaust hole 24 communicated with a communication path 23 is formed on an upper end of the projecting portion 22, and an exhausting portion 27 for communicating the air region portion 20 with the external, is disposed at a lower position with respect to the position of the exhaust hole 24. |
