The openings communicating between the chambers, A, A, and the induction, or foot-valve chamber, D, are covered by suitable valves, E, E, called suction valves, the valve seats, F, F, and valve guards, I, I, which latter prevent the valves from opening too far.
A third chamber, J, called the vacuum chamber, is situated behind the chambers, A, A, at their lower halves, and between them at their upper, or tapering halves, and communicates with them through the round opening in the induction, or foot-valve chamber, D.
A fourth chamber, called the discharge chamber, situated on the lower side of the working chambers, A, A, opposite to the vacuum chamber, J, and represented by the dotted lines in the sectional view communicates with each of the working chambers, A, A, by passages at the lower half of its intersection with these chambers. This discharge chamber contains the discharge valves, E, E, their valve seats, G, G, and the valve guards, I, I, which cover the passages leading from chambers, A, A.
The delivery pipe, H, connects with the discharge opening in the top of the discharge chamber by means of a flanged joint.
The induction, or foot-valve chamber, D, contains the valve, E, its valve seat, F, and the guard, I, which serve the purpose of holding the charge of water in the pump. The lower end of this chamber is connected to the suction pipe by a flanged joint.
Parts, K, K, are oval plates covering the openings through which the seat, valve and guard are inserted, to their respective chambers, and are fastened in position by means of clamps and bolts, N, N. The ends of these clamps fit loosely into suitable recesses and are thus held in position while the cover plates are being applied. Another set of similar clamps and bolts serve in a like manner, to fasten the seats, valves and guards in place.
The object in employing four openings to the pump, instead of two, is to make it possible and convenient to get at the interior for examination, and easy to remove all deposit that may form on the walls of the chambers which could not be reached otherwise.
Vent plugs are inserted in the cover plates for the purpose of draining off the water in the pump to prevent freezing.