SERVICE (Cont) - TM-55-1905-219-14-110553

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SERVICE (Cont)

TM-55-1905-219-14-11 Landing Craft Utility (LCU) 1667 Class Boston Hull Numbers 1667-1670 NSN 1905-00-168-5764 Manual

Testing for leaks.

TM 55-1905-219-14-11

5-144. REFRIGERATOR/FREEZER - MAINTENANCE INSTRUCTIONS

(Continued).

LOCATION

ITEM

ACTION

REMARKS

REPAIR (Cont)

(4)

Turn the low-side valve inward, so that the compressor crankcase is opened to the compound gauge

and to the hose which leads to the cylinder for fresh refrigerant. Start the compressor; watch the compound gauge, and

then open the valve on the service cylinder. A competent serviceman should add the proper amount of refrigerant to the

corresponding temperature and pressure of the system.

How to pump refrigerant back into the receiver.

(1)

When it is necessary to open, or remove for repairs, the expansion valve, expansion coil, or the

suction line, all the refrigerant must be pumped back into the receiver and condenser - if it is to be used again after the

repairs are complete. The receiver and condenser will hold the entire charge of refrigerant.

(2)

Attach a compound gauge to the low-side or suction valve, and a pressure gauge to the high-side or

discharge shut-off valve, purging the connections in the usual way. After the gauges are attached, turn both valves back

one turn for reading; now close the receiver valve to shut-off the receiver from the liquid line going to the expansion

valve.

(3)

Then, start the compressor and run it until the compound gauge shows approximately 5 lbs. This

operation pulls 'the refrigerant all the way around through the system in the direction of the arrows shown on master

drawing and forces it into the condenser and receiver. When the 5 lb. pressure is reached, it is almost certain that all the

refrigerant is pumped back into the condenser and receiver. At this point, the unit can be stopped, and the high-side

shut-off valve closed to prevent any refrigerant vapor going back into the compressor should the compressor valves leak.

CAUTION

Never open a vacuum system as air will rush in to replace the vacuum and will probably

draw some moisture into the system.

(4)

With the refrigerant back into the condenser and receiver, any part can be removed from the unit with

the exception of the high-side shut-off valve, the condenser and the receiver. These parts still have refrigerant in them.

5-1461