Huawei NetCol500-A080 - Page 39

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Low-pressure needle valve
1. Leak checking
2. Vacuuming
3. Precharging refrigerant
• The pressure gauge on the left is a low-pressure gauge, and the one on the right is a
high-pressure gauge.
•
The needle valve specification is 7/16-20UNF.
Scenario Without a Low Temperature Component
(NetCol8000-A045/A055/A090 Downflow)
The figures use a single-system unit as an example. You need to perform leak checking,
vacuuming, and precharging refrigerant on both systems of a dual-system unit.
Nut
Reducing valve
Vacuum pump
Exhaust pipe
needle valve
Scenario Without a Low Temperature Component
(NetCol8000-A060/A120 Downflow)
Nut
Reducing valve
Vacuum
pump
Low-pressure needle valve
1. Leak checking
2. Vacuuming
3. Precharging refrigerant
Exhaust pipe
needle valve
Electronic
scale
Refrigerant cylinder
Nitrogen
cylinder
Refrigerant cylinder
Electronic scale
Nitrogen cylinder