Thermo King MD-MT, Operator'S Manual

Page: 123 / 192

Refrigeration Service Operations
123
Suction Line Check Valve and
Purge Check Valve
Replacement (SLCV, RSLCV,
and PCV)
Removal
1. Pump down the low side and equalize the
pressure to slightly positive.
2. Unsolder the lines and remove the check
valve.
NOTE: Disassemble the valve before
unsoldering.
Installation
1. Clean the tubes for soldering.
2. Place the disassembled check valve in
position. The arrow on the valve body
indicates the direction of refrigerant flow
through the valve.
3. Solder the inlet and outlet connections. After
the valve cools, reassemble the valve.
4. Pressurize the low side and test for leaks.
5. If no leaks are found, evacuate the system.
6. Open the refrigeration valve and place the unit
in operation. Check the compressor oil.
In-Line Check Valves
This unit uses some in-line check valves. An
in-line check valve is not repairable and must be
replaced if it fails. A heat sink must be used on the
in-line check valve when it is being soldered in
place to prevent damage to the neoprene seal.
Removal
1. Remove the refrigerant charge (for the liquid
return check valves the unit can be pumped
down instead).
2. Place the heat sink on the check valve.
3. Unsolder the lines and remove the check
valve.
Installation
NOTE: A heat sink must be used on the in-line
check valve when it is being soldered in place to
prevent damage to the neoprene seal.
1. Clean the tubes for soldering.
2. Place the check valve in position. The arrow
on the valve body indicates the direction of
refrigerant flow through the valve.
3. Place a heat sink on the check valve.
4. Solder the inlet and outlet connections.
5. Pressurize the refrigeration system and test for
leaks.
6. If no leaks are found, evacuate the system.
7. Recharge the unit with the proper refrigerant
and check the compressor oil (if pumped
down, open the refrigeration valves instead).
1. Spring 3. Neoprene Seal
2. Valve 4. Valve Seat
Figure 67: Cross Section of In-Line Check Valve