| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in which when rise and drop of temperature are repeated, inflow of an fire-extinguishing fluid aqueous solution from a primary pipe 60 to a secondary pipe 50 and discharge of the fire-extinguishing fluid aqueous solution from the secondary pipe 50 occur repetitively, resulting in a reduction in pressure in the primary pipe 60.SOLUTION: A pressure rise preventing valve is provided between a primary pipe 60 and a secondary pipe 50, the pressure rise preventing valve having a chuck valve mechanism which releases, when the pressure of the secondary pipe 50 becomes higher than the pressure of the primary pipe 60 by a predetermined value or more, the pressure of the secondary pipe 50 to the primary pipe 60. A drain valve 15 which discharges water when the pressure of the primary pipe 60 becomes a fixed value or more, is provided on the primary side of a mixer 5. |
