Economizer Expansion Valve Replacement

Remove the economizer expansion valve as follows:

1. Some units have a receive tank outlet valve, if the unit does perform a low side pump down and isolate the low side by closing the compressor service valves. If the unit does not have an outlet valve recover the refrigerant charge from the unit (Refer to Recovering Refrigerant from System).

2. On the feeler bulb carefully remove the outer insulation, to be reused. Remove cork tape from around element.

3. Unclamp feeler bulb from the suction line in the condenser section.

4. Clean element bulb tube holder and tube.

5. Heat and unsolder the inlet and outlet lines from economizer expansion valve.

6. Remove the old economizer expansion valve from unit and discard.

Install the economizer expansion valve as follows:

1. Clean the inlet and outlet lines for soldering.

2. Place new economizer expansion valve in position.

   Open
   		1	Economizer Heat Exchanger
   		2	Economizer Expansion Valve
   		3	Vapor Injection Line
   		4	Feeler Bulb Line

3. Solder inlet and outlet line connections to economizer expansion valve and clean solder connections with baking soda. Apply black paint to area to prevent corrosion.

   Note Thermo King strongly recommends that dry nitrogen be used to purge the system during any solder operations (Refer to Using Pressurized Nitrogen).

4. Pressurize the refrigeration system or the low side and check for leaks (Refer to Leak Testing Refrigeration System).

5. If no leaks are found, recover the refrigerant used for the leak test (Refer to Recovering Refrigerant from System).

6. Evacuate the system or the low side (Refer to Evacuation and Cleanup of Refrigeration System).

7. Locate feeler bulb in former position. The feeler bulb must make good contact or operation will be faulty. Apply heat transfer paste to element bulb holder and install bulb. Install clamp and tighten until bulb will not shift. See photos below.

   	Open	Open
   1	Apply heat transfer paste to bulb holder before installing TXV bulb.
   2	Tighten clamp to verify bulb is secure.

8. Apply cork tape around element making sure all air pockets are removed. See photos below.

   	Open	Open
   1	Wrap feeler bulb with cork tape.
   2	Verify bulb is fully covered.

9. Apply the insulation removed in step 2 of Removal above. See photo below.

10. Apply cork tape to the complete TXV valve. See photo below.

    	Open	Open
    1	Apply insulation to feeler bulb (reuse insulation that was removed).
    2	Seal TXV valve with cork tape including feeler bulb line.

11. If low side pump down was performed open compressor service valves. Otherwise, recharge the unit with R-404A/R-452A (Refer to Charging System with Refrigerant).

12. Start unit and perform a PTI to check performance.