Refrigeration Service Operations
143
Expansion Valve Assembly
Removal
1. Pump down the low side and equalize the
pressure to slightly positive.
2. Remove the evaporator access panels.
3. Remove the feeler bulb from the clamp. Note
the position of the feeler bulb on the suction
line.
4. Unsolder the equalizer line, inlet liquid line
and distributor from the expansion valve.
5. Remove the expansion valve mounting bolt
and remove the expansion valve from the unit.
Installation
1. Install and bolt the expansion valve assembly
in the unit.
2. Solder the equalizer line, inlet liquid line and
distributor to the expansion valve.
3. Clean the suction line to a bright polished
condition. Install the feeler bulb clamps and
the feeler bulb on the side of the suction line
in its former position. The feeler bulb must
make good contact with the suction line or
operation will be faulty. Wrap with insulating
tape.
4. Pressurize the low side and test for leaks. If no
leaks are found, evacuate the low side.
5. Replace the access panels.
6. Open the refrigeration valves and place the
unit in operation.
7. Test the unit to see that the expansion valve is
properly installed.
Heat Exchanger
Removal
1. Pump down the low side and equalize the
pressure to slightly positive.
2. Remove the evaporator access panels.
3. Remove the mounting bolts that hold the heat
exchanger on the bulkhead.
4. Unsolder the equalizer line from the suction
line.
5. Unsolder the liquid outlet line from the
expansion valve.
6. Note the position of the feeler bulb on the side
of the suction line. Remove the expansion
valve feeler bulb from the suction tube.
7. Unsolder the suction line at the evaporator coil
end.
8. Unsolder the remaining outlet suction line and
inlet liquid line connections. Remove any
putty from around the lines before unsoldering
the connections.
9. Slide the heat exchanger assembly out of the
evaporator housing.
Installation
1. Clean the tubes for soldering.
2. Place the heat exchanger assembly in the
evaporator housing and install the mounting
hardware loosely.
3. Solder the liquid inlet and the suction outlet
line connections on the curbside of the
evaporator. Seal the openings through the
bulkhead with putty when the refrigerant lines
have cooled off.
4. Solder the suction line connection to the
evaporator coil.
1.
End View
2.
Side View
Figure 225: Location of Expansion Valve Bulb
AEA713
