| 摘要 |
PROBLEM TO BE SOLVED: To reduce a discharge quantity of water from a water pipe 11 by promoting thawing of an operation chamber, in a freezing preventive device 1 provided with a cylindrical body 2 connected to the water pipe, an inflow chamber 4 communicating with the water pipe provided in the body, a body inner drain passage 5 having a valve port 51 communicating with the inflow chamber on the upper end and extending downward from the valve port, a body inner cylindrical operation chamber 6 for enclosing the drain passage, a valve element 7 for sealing the operation chamber from above and capable of blocking up the valve port from above and a spring 8 for energizing the valve element to the lower closing side, and discharging the water in the water pipe from the inflow chamber via the valve port and the drain passage, by moving the valve element to the upper opening side against energization force of the spring by the expansion pressure resulting from the freezing-expanding of the water in the operation chamber, in the freezing preventive device 1 installed in the water pipe.SOLUTION: When a valve element is moved to the upper opening side, a valve port is opened, and sealing of an operation chamber by the valve element is released, and water in a water pipe flows in the operation chamber from above via an inflow chamber. |
