Brazing; Evacuation - Hoshizaki Steelheart Series Service Manual

2. Brazing

Risk of Fire or Explosion Flammable Refrigerant Used
• Servicing shall be done by factory authorized service personnel to minimize the risk
of possible ignition due to incorrect parts or improper service.
Risque De Feu Ou D'Explosion Le Frigorigène Est Inflammable
• L'entretien doit être effectué par le personnel de service autorisé par le fabricant
afin de minimiser les risques d'inflammation attribuables à l'installation d'une pièce
inadéquate ou à la mauvaise exécution du service.
• Wear appropriate personal protective equipment (PPE) when servicing the
appliance.
• You must have a combustible gas leak detector in the immediate work area at all
times.
• You must have a Class B chemical fire extinguisher available at all times.
• Notify all persons in the immediate area that you are working with a flammable
refrigerant.
• Do not use silver alloy or copper alloy containing arsenic.
• Be sure the area is clear of refrigerant vapor before brazing.
1) Prior to brazing, purge with nitrogen gas for 2 min., flowing at a pressure of 3 to 5 PSIG.
WARNING! Purging with nitrogen gas assures all refrigerant has been removed
from the refrigeration circuit.
2) Braze/repair/replace damaged component or fittings while purging with nitrogen gas,
flowing at a pressure of 3 to 5 PSIG.
• 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.
Install the new drier with the arrow on the drier in the direction of the refrigerant
flow.
• When brazing, protect the drier by using a wet cloth to prevent the drier from
overheating. Do not allow the drier to exceed 250°F (121°C).
3) Use soap bubbles to check for leaks. Raise the pressure using nitrogen gas (190 PSIG).
Do not use any refrigerant as a mixture with pressurized air for leak testing.
4) Once leak checking is complete, release the nitrogen gas from the system.

3. Evacuation

1) Attach a vacuum pump to the system. Be sure the high-side charging hose is connected
to the field-installed high-side access valve.
DANGER
WARNING
NOTICE
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