36
D. Removal and Replacement of Hot Gas Valve
IMPORTANT
1. Always use a copper tube of the same diameter and length when replacing
the hot gas line; otherwise the performance may be affected.
2. Always install a new drier every time the sealed refrigeration system is
opened. Do not replace the drier until after all other repair or replacement
has been made.
3. Always replace the strainer when replacing the hot gas valve.
1) Turn off the power supply.
2) Remove the panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the screw and the solenoid.
5) Disconnect the valve and strainer.
6) Place the new valve and strainer in position.
7) Remove the drier, then place the new drier in position.
8) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
CAUTION
Always protect the valve body by using a damp cloth to prevent the valve from
overheating. Do not braze with the valve body exceeding 250°F (121°C).
9) Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of
refrigerant to the system (if using an electronic leak detector), and then raise the
pressure using nitrogen gas (140 PSIG). DO NOT use R-404A as a mixture with
pressurized air for leak testing.
10) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.
11) Cut the leads of the solenoid allowing enough lead length to reconnect using closed
end connectors.
12) Connect the new solenoid leads.
13) Attach the solenoid to the valve body and secure it with the screw.
14) Replace the panels in their correct positions.
15) Turn on the power supply.
