head
and try the other indicator plug or cylinder cock. If a leaky by-pass
valve in the front end is the trouble, no steam will come through. To
test the low-pressure piston packing, place the engine in the same
position, lever in position to admit steam into the front end of
high-pressure cylinder. Open starting valve, remove back indicator plug
of low-pressure cylinder and give engine steam; if steam comes from the
indicator plug opening or open back cylinder cock, either packing or
by-pass is leaking. To determine which one, put reverse lever in another
position, close back indicator plug and open forward one; if blow still
continues, the packing rings are leaking or else both by-pass valves.
Would then inspect the by-pass valves.

29. Q. How can the blow through sleeve packing between high and
low-pressure cylinder of the tandem compound be located?

A. Place the engine as before on the top quarter, put reverse lever in
forward gear, see that starting valve is closed, block the drivers or
set the brakes solid and open the throttle. Until the engine moves,
unless there is a leak, no steam can get into the front side of the
low-pressure cylinder. Remove the indicator plug in front end of the
low-pressure cylinder for this test.

30. Q. How test for piston packing blow with balanced compound?

A. For a Baldwin balanced compound to test the high-pressure piston
packing, place the engine with the outside main pin on that side of the
engine on the bottom quarter, the reverse lever in the forward notch,
starting valve closed, set the brakes solid or block the drivers, remove
the indicator plug in the front end of either the high or low-pressure
cylinder. With throttle open this will admit steam to the back end of
high-pressure cylinder. Steam coming out of this plug opening, will
indicate a leak past the piston or the high-pressure valve. If
uncertain, next test the high-pressure valve by moving the reverse lever
to the center notch. This should cover the ports and if the valve is
tight the blow will stop. To test the low-pressure piston, place the
engine in the same position with wheels blocked, starting valve open,
back indicator plug out; when throttle is opened, the leaky packing will
be shown by steam issuing from the plug opening. If uncertain, the valve
can be tested by bringing reverse lever to the center of quadrant, which
will spot valve over port and if it is tight the blow will stop. In any
compound engine