| 摘要 |
<p>PURPOSE:To prevent the reverse flow of dirty water in a water feed tank for a building or the like by providing a baglike plug for enclosing gas at the upper part of a rigid container inside, making a liquid runable into/out of a space between the plug and a container inside wall through the inflow opening and the outflow opening of the liquid at the lower part of the container, and letting the plug clog up the inflow and outflow openings when the liquid is gone. CONSTITUTION:A baglike plug 3 is provided in a hollow rigid container 2 of airtight structure, and is fitted to the lid flange 6 of the container 2, and air is enclosed into the plug 3 through an air enclosing valve 5. Liquid inflow piping 51 and outflow piping 61 are provided at the lower part opening portion 41 of the container 2, and a liquid is run into/out of a space between the plug 3 and the inner wall of the container 2. The inflow opening 52 of the inflow piping 51 is fixed at a retainer member 4, and the outflow opening 6 of the outflow piping 61 is fixed at a lower flange 9, and when the inside of the container 2 becomes empty, arrangement is made so that the plug 3 may clog up the inflow opening 52 completely. Accordingly, even at the times of power failure and a water-raising pump accident, reverse flow due to a siphon phenomenon or the like can be prevented beforehand by a water feed tank portion, and high safety can be maintained.</p> |
