===========+===========+========+========================= | | | | | | Approximate Space | | | Occupied | | | Inches | | +--------+-------+-------- Diameter of|Diameter of| Length | | | Steam | Water | of | Height | Depth | Width Cylinders | Pistons | Stroke | | | -----------+-----------+--------+--------+-------+-------- 4-1/2 | 2-3/4 | 4 | 38 | 18 | 23 5-1/4 | 3-1/2 | 5 | 46 | 22 | 29 6 | 4 | 6 | 50 | 23 | 32 | | | | | 6 | 4-1/2 | 6 | 50 | 23 | 32 7-1/2 | 5 | 6 | 54 | 28 | 33 9 | 6 | 6 | 57 | 27 | 36 | | | | | 7-1/2 | 4-1/2 | 10 | 66 | 28 | 33 9 | 6 | 10 | 68 | 27 | 36 10 | 7 | 10 | 77 | 34 | 40 | | | | | 12 | 8-1/2 | 10 | 86 | 39 | 44 12 | 9-1/4 | 10 | 86 | 39 | 44 14 | 10 | 15 | 110 | 36 | 50 -----------+-----------+--------+--------+-------+-------- A notable feature in this pump is the location of the exhaust passage; _this opening is underneath the cradle_—or the part that the pump rests upon—just forward of the steam cylinders. The flanges of the steam end and cylinders and the steam chest cover have been made heavier than the regular and strengthened to withstand the higher pressures. Fig. 305 is a sectional view of a larger size duplex pump than the one shown in Fig. 302. The plunger, B, packing is identical, but the number of water valves is double; access for cleaning the suction chamber, C, is had by removing the hand hold plate at the side and in the center. The discharge valves are reached through the hand hold at D. [Illustration: FIG. 305.] SETTING THE VALVES OF THE DUPLEX PUMP. _The following rule applies to nearly all duplex pumps of the Worthington type._ The valves are usually of the common “^D^” valve type, working on the cylinder iron, or bronze seats, and suitably “set.” Sufficient cushion at the end of each stroke is provided by separate valves in the ports.