Containment, Recovery and Handling Practice
Containment first
Good practice is a hierarchy: prevent the leak, detect it early, repair it promptly, and only then recover. Common leak points are joints, flare connections, valve stems, Schrader ports, sight glasses and vibration-prone pipework. Questions often present a scenario and ask for the first correct action - usually isolate, make safe, then recover what remains rather than topping up and walking away.
Recovery technique
Recovery means removing refrigerant into a suitable container without venting it to atmosphere. Key concepts: recovery cylinders must be appropriately rated, in test, colour-coded and clearly labelled with the refrigerant identity; never mix refrigerants in one cylinder; never fill above the marked fill limit; weigh the cylinder before and after to quantify what was recovered. Recovery equipment should be purged correctly between refrigerants to avoid cross-contamination. Venting is only lawful in tightly defined circumstances, and "it's a small amount" is never one of them.
Traps in questions
- Confusing recovery (into a cylinder), recycling (cleaning on site for reuse) and reclaiming (off-site reprocessing to specification).
- Assuming a recovered charge can simply be recharged into any system - it must be identified and of suitable quality.
- Overfilling a cylinder because it was "only liquid" - liquid fill limits exist for a reason.
- Forgetting that the recovery cylinder must be evacuated before use.
Worked example
A system holds 6 kg R-410A. You recover into a 12 kg cylinder already containing 2 kg of the same refrigerant. Available headroom is governed by the fill ratio (typically around 0.8 kg per litre of water capacity), not by nominal cylinder size - always check the stamped fill limit and weigh, never guess. Record start and finish weights so the recovered mass is traceable.