Hoshizaki KM-320MAH - Manual (Page 38)

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6) Braze the new expansion valve, with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
WARNING
1. Do not heat the wall. Place a steel barrier for protection.
2. 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).
7) Install a new drier.
8) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.
9) Evacuate the system and charge it with refrigerant. See the nameplate for the required
refrigerant charge.
10) Attach the bulb to the suction line in position. Be sure to secure it with clamps and to
insulate it.
11) Place the new set of expansion valve covers in position.
12) Replace the panels in their correct positions.
13) Turn on the power supply.
F. Removal and Replacement of Hot Gas Valve and Line Valve
CAUTION
Always use a copper tube of the same diameter and length when replacing the
hot gas lines; otherwise the performance may be reduced.
IMPORTANT
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.
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 hot gas valve or line valve using brazing equipment.
6) Install the new valve.
WARNING
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).