| 摘要 |
<p>Auxiliary water is supplied to a building, which also receives water from a main supply line, from an external portable tank separate from the main supply line. The water is pumped from the tank through an auxiliary supply line to a junction with the main supply line. One-way valves are provided in both the main supply line and the auxiliary supply line before the junction to prevent backflow in each of the supply lines from the other supply line. Water is pumped to the auxiliary supply line at a prescribed pressure which is less than the main supply line pressure so that the valves allow water to be drawn only from the main supply line until a loss of main line pressure at which point the valves automatically cause the greater auxiliary supply line pressure to cause water to be drawn only from the auxiliary supply line.</p> |
