i STEAM COAL - Clpdigital.org

30 THE COAL TRADE BULLETIN.
chamber bonnets, and EE are exhaust ports leading
from the ends of the steam-chest direct to
the main exhaust and closed by the reversing
valves II. Thus in further explanation of the
operation: C, the piston, is driven by steam admitted
under the slide valve G, which, as it is
shifted backward and forward, alternately connects
opposite ends of ->the cylinder A with the
live steam pipe and exhaust. This slide valve
G is shifted by the auxiliary plunger F; F is
hollow and filled with steam, which, issuing
through a hole in each end, fills the spaces be-
Fig. 3—Parts of Regular Horizontal Pumps.
tween it and the heads of the steam chest in
which it works. Pressure being equal at each
end, this plunger F, under ordinary conditions.
is balanced and motionless; but when the main
piston G has traveled far enough to strike and
open the reverse valve I, the steam exhausts
through the port EE from behind that end of the
plunger F which, immediately shifts accordingly
and carries with it the slide valve G, thus reversing
the pump. No matter how fast the piston
may be traveling, it must instantly reverse on
touching the valve I. In its movement the plunger
F acts as a slide valve to close the port EE,
and is cushioned on the confined steam between
the ports and steam-chest cover. The reverse
valves II are closed as soon as the piston C leaves
them, by a constant pressure of steam behind
them, conveyed direct from steam chest through
the ports shown by dotted lines.
Fig. 2 shows the Cameron water valve chest and
arrangement of valves. The right-hand side is
shown in full as it appears when the bonnet is
removed and the left-hand side in section. The
superiority of this valve chest lies in this accessibility.
By simply removing one bonnet or cover
the whole interior with every valve is plainly
visible, turned inside out, so to speak, and not a
speck of anything that may have lodged there
can escape detection. The shelves or decks are
bored out tapering, and the brass seats forced in.
They can thus be readily taken out and renewed
at any time. Each stem holds two valves, with
their springs one above the other, so that by
simply unscrewing one plug and pulling up the
stem both are released. It
will be noticed that the Cameron
valve chest is placed
close to the ground and beside
the water piston, instead
of above it. The valves
are, therefore, so much nearer
the water and the suction lift
is reduced accordingly. Every
pump has two suction openings,
one on each side, and
the discharge opening can be
turned in any direction desired.
Fig. 3 shows an arrangement
of detail parts of the
regular horizontal piston
pump for general service; the
construction of every part can
readily be noted. A list of
names and number of each is
also given, being as follows:
Fig. 4— Vertical Plunger
Sinking Pump.
101, steam cylinder; 102, steam chest; 103,
steam chest plunger; 104, steam chest cover; 105,
steam chest crank and nut; 106, steam chest crank
handle; 107, steam chest, stuffing box bottom;
108, steam chest, stuffing box cap; 109, slide valve;
110, steam cylinder cover; 111, reversing valve;
112, reversing valve bushing; 113, reversing valve
cap; 114, reversing valve plug; 115, steam piston
head; 116, steam piston head, or follower—the
head has a taper hole and the follower a straight
hole; 117. steam piston head; 118, steam piston
follower; 119, steam piston follower; 120, steam
piston packing ring, with wedge and spring;
121, steam piston packing ring; 122, steam piston