Choosing the Right Recovery Cylinder for a Mixed Charge
You are clearing a plant room containing three systems. System A holds R-134a. System B holds R-407C. System C is an old R-22 unit that is being decommissioned. You have four recovery cylinders: two grey-bodied cylinders marked R-134a, one marked R-407C, and one unmarked cylinder that a previous engineer left behind. All cylinders are in test. The R-22 system is still running and the customer wants it decommissioned today. The unmarked cylinder is roughly half full of an unknown liquid.
1. How do you allocate cylinders and handle the unmarked cylinder?
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Each refrigerant gets its own dedicated cylinder - never mix different refrigerants, because a mixed charge cannot be reclaimed to specification and becomes difficult and costly to dispose of.
- R-134a → its dedicated cylinder.
- R-407C → its dedicated cylinder.
- R-22 → a cylinder suitable for R-22 (not one of the R-134a or R-407C cylinders). If none is available, I do not start the R-22 recovery until I have the correct cylinder.
The unmarked half-full cylinder is a problem: I cannot assume its contents. It must not be used for any of these refrigerants. I would treat it as unknown, label it as such, keep it segregated, and have it identified/analysed or sent for proper disposal by a competent waste contractor. It should never be topped up or blended into another cylinder.
All cylinders must be in test, not overfilled (fill limit by weight, typically leaving ullage), and labelled with the refrigerant and quantity.
2. After recovery, what determines whether each refrigerant can be reused, reclaimed or must be destroyed?
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It depends on the condition and intended use:
- Reuse in the same owner's equipment: refrigerant recovered and cleaned (recycled) on site may be put back into the same system, provided it meets the required purity.
- Reclaim: if it is to go into another owner's equipment or be sold on, it must be sent to a reclamation facility and certified to the relevant purity standard (e.g. AHRI 700). Reclaimed refrigerant carries documentation of composition and purity.
- Destruction: contaminated, mixed, or unidentifiable refrigerant (such as the contents of the unmarked cylinder, once identified as unusable) must go for destruction via an authorised waste route, with the transfer documented.
R-22 is an ODS (HCFC) and is subject to phase-out and separate handling; recovered R-22 must not be vented and must be reclaimed or destroyed. Every movement is recorded: quantity, refrigerant type, and destination.