| 摘要 |
PROBLEM TO BE SOLVED: To prevent city water from being contaminated by sucking contaminated water in a sucking operation even when the contaminated water accumulates in a manhole. SOLUTION: This air vent valve 10 for city water is provided with a valve body 13 connected to a water pipe, a float valve body 15 floating and sinking in the valve body 13, and a lid 16 covering an upper part of the valve body 13 and having an air opening 18 opened and closed by the float valve body 15. The air vent valve 10 for city water is provided with a contaminated water suction prevention mechanism 20, and the air vent valve 10 for city water is arranged in an underground manhole, and elimination of air from the inside of the water pipe and suction of the air into the water pipe are performed. When the contaminated water accumulates in a cavity in the manhole, the suction of the contaminated water from the air opening 18 is prevented by the contaminated water suction prevention mechanism 20. COPYRIGHT: (C)2013,JPO&INPIT |
