TM 55-203
Figure 11-5. Automatic temperature-controlled vapor system.
When the car is shopped, the valve should be
11-8. Maintenance and Repair
disassembled and checked for wear, particularly the main
a. General. The two essential factors of steamheat
valve and seat. The bleeder valve, pins, cams, and
maintenance are the prevention of train delays through
levers should be checked for wear upon reassembly; the
steam-heat failures and the provision of car comfort for
valve should be tested under high-pressure steam for
passengers. This type of maintenance must often be
leaks and proper functioning.
performed during short layover periods at terminals. A
maintenance program will include thorough inspection
annually, preferably prior to the beginning of the heating
trainline crosses and tees, should be removed and
season. The principal sources of trouble are discussed
cleaned when a car is shopped. Normally, this is
below.
adequate attention.
b. End Train-Pipe Valves. The valve should be
d. Vapor Cutout and Drain Valve. The cutout and
operated from the platform to see that the linkage is in
drain valve located in each branch pipe should not require
operating condition and, also, from the weighted ball-type
maintenance if thoroughly overhauled when a car is
handle, to check the hold-open feature of the valve. In
shopped. If a constant steam leak exists at the drain port,
most cases, the valve stem will need repacking or the
it usually is indicative of a faulty back seat in the valve.
addition of a packing ring. The stem should have
This can be corrected by grinding the seat. This seat
sufficient packing so that subsequent packing nut
tightenings can be made by car inspectors as required.
11-4
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