Refrigerant recovery equipment (machine, tank, scale) — use, maintenance, fault diagnosis

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Recovery equipment composition and standard recovery procedure. Check: Equipment composition: ① Recovery machine — pulls refrigerant from the system and condenses/pressurizes into the tank. Common machines move 1–3 kg/min. AHRI 740 certified preferred. ② Recovery tank (DOT-4BA/4BW or equivalent) — pressure vessel, store separately by gas type. 80% fill limit (safety margin). ③ Digital scale — weighs the tank to track recovered/remaining amount. ±10 g precision. ④ Accessories — recovery hoses (high-pressure rated, ≥250 PSI), manifold, pinch-off kit (emergency leak isolation). Standard recovery procedure: ① Identify the system → choose the right tank. ② Connect hoses/manifold (low and high side). ③ Run recovery until system pressure reaches 0 to −5 PSI (slight vacuum). ④ Stop the machine → wait 5 minutes → confirm pressure does not rise again. If it does, recover further. What to do: Safety items: ① Never exceed the 80% fill limit of the recovery tank — liquid expansion at higher temperature can cause rupture. Always monitor weight with the digital scale. ② Recovering flammable refrigerants (R-32, R-290, R-454B) — use dedicated machines and tanks, ventilate, and ground for static. ③ Recovery machine fault — slow recovery rate = worn machine compressor or hose leak. The Schrader core in the recovery hose can also be obstructed. ④ When disconnecting hoses after recovery, residual gas escapes — for flammables, do this in a ventilated area. Cap both ends of each hose to seal until next use. ⑤ After recovery, use the identifier to check any residual gas in the system. Diagnosing equipment faults — slow recovery rate, machine noise, overheating. Check: Check: ① Low rate (less than 50% of maker spec per minute) — a) machine compressor wear, b) hose blockage (Schrader core), c) machine filter clogged, d) recovery tank full (recovery nearly halts beyond 80%). ② Heavy vibration or noise during recovery — bearing wear in the recovery machine, or liquid refrigerant entering directly ('liquid push' before condensing). Hose diagnostic: with the hose disconnected from the system, run the machine alone and measure pressure at the hose end — normal is ~10–15 mbar vacuum. Weak pressure change = hose or core blockage. ③ Machine shell overheats — surface >70°C (normal 50–65°C). Suspect poor ventilation, low oil in machine compressor, or clogged condenser. What to do: Action: ① Hose / Schrader core blockage → clean hose or replace the core. A core costs ~$1; recommend periodic replacement after 5 years. ② Machine filter → replace per maker manual every 6–12 months. ③ Recovery machine compressor wear → factory service. Frequent use gives ~5–7 years of life. ④ Prevent 'liquid push' → connect both liquid and vapor lines during recovery and use a liquid trap accessory if available. ⑤ Shell overheating → check ventilation (30 cm clearance), inspect oil in the machine compressor (maker manual). ⑥ Tank-full check — compare digital scale reading vs the tank's tare weight on its nameplate; switch to a new tank before reaching the 80% fill limit.

Refrigerant recovery equipment (machine, tank, scale) — use, maintenance, fault diagnosis

Likely causes

Recovery equipment composition and standard recovery procedure

Diagnosing equipment faults — slow recovery rate, machine noise, overheating

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