Westinghouse 5026 Instruction Pamphlet page 29

57
;;6
CROSS COMPOUND AIR COMPRESSORS
connection to the governor is used, leave the main reser ­
voir cock open and close the brake pipe cut-out cock
under the brake valve and the cut-out cock in the sup­
ply pipe to the distributing valve and place the brake
valve handle on lap. If no cut-out cock is used, as with
the A-I Equipment, place the brake valve handle on
lap. Bleed down reservoir pressure to about 62 or 63
T'
pounds. Allow the pressure to leak down to 60 pound"
to settle down to an equalization of tempera-
Fig. 22. Disassembled View and Sectional View of Disc Holder
with Disc
tures) and note the amount of drop from this pressure
during one minute. This drop must not exceed 2 pounds.
If a greater leakage than this exists, it must be reduced
to this limit before proceeding with the compressor test,
otherwise the test would indicate a poorer condition of
the compressor than is the case, due to extra labor re ­
quired to maintain this leakage.
After the main reservoir and its connections have
been tested for leakage as above, the compressor should
be tested as follows:
The orifice disc is placed in a Apecial holder, Fig.
22, supplied for this purpose which should be connected
to the main reservoir drain cock, as illustrated in Fig. 23,
REPAIR SHOP AND HOAD TESTS
with a test gage inserted between the disc holder and
drain cock. Then close the main reservoir cut-out cock
if the SD (or SF) governor is used; if, however, the SO
type of governor or the SF type with a manifold provid ­
ing for a single main reservoir connection to the gov­
ernor is used, leave the main reservoir cock open and
close the brake pipe cut-out cock under the brake valve
and the cut-out cock in the supply pipe to the distribut ­
ing valve and place the brake valve handle on lap. If no
Fig. 23. Showing Orifice Disc Holder and Gage Connection to
Main Reservoir Drain Cock
cut-out cock is used, as with the A-I equipment, place
the brake valve handle on lap. Then start the compres ­
sor and raise the pressure in the main reservoirs to slight ­
ly below 60 pounds. Open the drain cock to the orifice
and throttle the steam supply to the compressor until