======================================================================== Rate of Flow | | | | | in Gallons | | | | | Per Day | 1/2" Pipe | 5/8" Pipe | 3/4" Pipe | 1" Pipe | 1-1/4" Pipe -------------+-----------+-----------+-----------+---------+------------- 3500 | 13.95 | 4.81 | 2.35 | 0.66 | 0.25 7000 | 47.17 | 17.30 | 7.45 | 2.04 | 0.74 14000 | 163.09 | 57.8 | 25.00 | 6.64 | 2.41 ======================================================================== The table shows how much additional elevation is needed over the 20 feet already referred to. For example, suppose it is decided that a rate of 1 quart in 10 seconds is to be maintained from three faucets or a rate of 7000 gallons per day. Suppose that a pond 4000 feet away is found to be 50 feet above the highest faucet in the house, and it is a question what size pipe ought to be used. By the table a 1-inch pipe loses 2.6 feet per 100 feet or 104 feet in the 4000 feet, an impossible amount when only 50 feet are available, although the size would be entirely proper if the difference of level was 124 feet or anything greater. A 1-1/4-inch pipe, however, loses only 0.74 foot in 100 or 39 feet per mile, so that the 1-1/4-inch pipe would be necessary, although that size would answer even if the pond were a mile and a quarter away. When water from a well is pumped to an elevated tank there is the same necessity of providing about 20 feet difference in level between the tank and the highest fixture, but the length of pipe involved being small, the friction losses are not great. It should be noted even here that too small a pipe may reduce the pressure, a 1/2-inch pipe causing a loss of 47 feet in a 100-foot pipe line. If a tower is built by the side of the house, the distance down to the ground, across to the house, and up to the second floor would hardly be less than 50 feet, and this is a loss of 23-1/2 feet, which means that the tank would have to be set higher in the air by this amount. With a 3/4-inch pipe, it should go 3.7 feet, and with a 1-inch pipe but a foot higher than the level necessary to make the water flow out of the faucet at the rate already specified. CHAPTER VII _QUALITY OF WATER_