EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Hard
A technician is recovering refrigerant from a high-pressure appliance. There is concern that the refrigerant may be contaminated with non-condensables. What is the primary indicator that non-condensables are present in the recovery cylinder?
- AThe recovery cylinder becomes excessively cold.
- BThe recovery rate is unusually fast.
- CThe recovery unit cycles on and off rapidly.
- DThe pressure in the recovery cylinder is higher than the saturation pressure for the recovered refrigerant at a given ambient temperature.
Show answer & explanationAnswer & explanation
Correct answer: D. The pressure in the recovery cylinder is higher than the saturation pressure for the recovered refrigerant at a given ambient temperature.
Non-condensables (like air) do not condense at typical recovery temperatures and pressures. When present in a recovery cylinder, they add to the total pressure, resulting in a pressure reading that is higher than the saturation pressure of the refrigerant at the ambient temperature. This is the definitive sign of non-condensables.
Why the other options are wrong
- A. Excessive coldness usually indicates efficient liquid recovery or rapid pressure drop, not necessarily non-condensables.
- B. An unusually fast recovery rate is generally a good sign, indicating efficient recovery, not contamination with non-condensables.
- C. Rapid cycling of the recovery unit could indicate various issues, such as a clogged filter or low refrigerant flow, but not specifically non-condensables in the cylinder.
Non-Condensable Detection (Recovery Cylinder)
Identifying the presence of gases like air in a recovery cylinder, which can hinder efficient recovery and contaminate reclaimed refrigerant.
- Non-condensables increase the pressure in the recovery cylinder.
- Compare cylinder pressure to saturation pressure at ambient temperature.
- Excess pressure indicates non-condensables.
Memory trick: Pressure too high, that's the air's sly lie!