injector would handle it. Would next see that no obstruction was in the
feed pipe or strainer and that the feed pipe was free from leaks, and
that the injector was getting a sufficient supply of steam. If the
injector would not prime, would see whether overflow or heater valve
could open wide, or if overflow pipe was obstructed. If suction pipe was
very hot would blow water back into tank and let suction fill with cold
water. If possible, examine for obstruction in the steam priming tube
and water tubes. If it would prime and fail to deliver water to the
boiler, would see that the delivery tube was not obstructed and then
look for trouble at the boiler check. An obstruction in the tubes would
stop the injector working at once, while wear of the tubes or filling up
with scale would affect the injector gradually.

110. Q. What are the advantages of the combination boiler check and stop
valve?

A. A combination boiler check is fitted with a valve similar to a globe
valve and can be closed at will. Its advantage is that the boiler
pressure can be shut off from the check and the valve repaired without
cooling the boiler. This hand-operated valve can be closed to prevent
the boiler water passing back in case the check valve sticks up and
allows the boiler water to pass back to the injector when not working.

111. Q. How can a disconnected tank valve be opened without stopping?

A. Close the overflow or heater valve and turn steam back toward the
tank; this will usually lift the valve from its seat or turn it around
so it opens.

112. Q. What comprises the steam heat equipment on a locomotive?