Fig. 159.
In Fig. 160 is shown an air-chamber attached to a force-pump for the purpose of preventing shocks in the discharge, and for producing a steady flow; air-chambers are also frequently attached to suction pipes for a similar purpose.
According to the underlying principles of action thus far explained hundreds of thousands of pumps have been constructed and operated. It is beyond the limits of this volume—or any single book to give the names and details of these so-called “hand-pumps,” however, three approved styles are shown in Figs. 161, 162, 163.
Fig. 161 represents a double acting force pump used extensively on ship-board, wharves, around factories, mills, etc., and in residences, for tank pumping. On ships these pumps perform the three-fold purpose of filling boilers when cold, washing down decks and to satisfy government inspection as to fire protection; in service in mines they are unaffected by mine water, the working parts being made non-corrosive. It is claimed that a three-inch diameter cylinder with a stroke of four and a half inches with a 11⁄4-inch suction pipe and 1-inch discharge pipe will lift and force water 150 ft. high and has a capacity of ·28 gallons for each stroke, with the water not more than twenty-five feet below the pump.
Fig. 160.
Fig. 162 represents a two cylinder force pump; this has vertical single acting pistons actuated by one lever, producing the same results as a double-acting pump. It is claimed that the total lift and force, from supply to point of delivery, with the pump not more than twenty-five feet above water will attain one hundred feet; that a 3-inch × 4 inch cylinder, 11⁄2-inch suction and 11⁄4-inch discharge will deliver ·24 gallons of water for each stroke.
Fig. 163 represents a widely used type of suction pump, it is designed for vessels of not more than fifteen to twenty feet deep; for contractors who wish to pump large quantities of water from excavations, etc.; for irrigation or any other purpose where a compact and capacious pump is desired.