The gland at the top of the barrel, E, is composed of a
piece, D, of the same tubing as the barrel, sliding in a collar, C,
soldered to E. The bottom of D and top of E are bevelled to force the
packing against the plunger. The plates A and B, soldered to D and C
respectively, are drawn together by three or more screws. A brass door-knob
makes a convenient top for the plunger. When the knob touches A, the bottom
of the plunger must not come lower than the top of the delivery pipe, lest
the water flow should be impeded and the valve, V, injured. Round off the
end of the plunger, so that it may be replaced easily and without
disarranging the packing if pulled out of the pump.
The valves are gun-metal balls, for which seats have been prepared by
hammering in steel cycle balls of the same size. Be careful to select balls
considerably larger than the bore of the pipes on which they rest, to avoid
all possibility of jamming. An eighth of an inch or so above the ball,
cross wires should be soldered in to prevent the ball rising too far from
its seat.
[Illustration: FIG. 110.]
A convenient mounting for a hand pump is shown in Fig.
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