| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an on-off valve unit for fire-fighting equipment, capable of reducing water hammer when discharging water and shortening the time from a standby state till the start of water discharge. <P>SOLUTION: The on-off valve unit 1 includes an automatic valve 4, and an air mixing mechanism 5 provided on the secondary side of the automatic valve 4. The air mixing mechanism 5 includes an orifice 18 and an intake pipe 19 provided on the secondary side of the orifice 18. When the automatic valve 4 is turned to an open state, fire-fighting water passes through the orifice 18, the secondary side is turned to a negative pressure, air is introduced, and the fire-fighting water containing air bubbles is formed and reach an opening 3 to generate a water hammer pressure, however, the air bubbles in the fire-fighting water become a damper and the water hammer pressure is absorbed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
