EPA Section 608 Universal Certification ExamType I (Small Appliances)Hard
A technician is using a piercing-type access valve to recover refrigerant from a small appliance. After piercing the line, the technician notices that no refrigerant is flowing into the recovery cylinder, and the system gauge shows a low vacuum. What is the MOST likely cause of this issue?
- AThe recovery machine's purge valve is open.
- BThe piercing valve did not fully penetrate the tubing.
- CThe ambient temperature is too high.
- DThe recovery cylinder is overfilled.
Show answer & explanationAnswer & explanation
Correct answer: B. The piercing valve did not fully penetrate the tubing.
If a piercing valve doesn't fully penetrate the tubing, it won't create an open path for refrigerant flow. The system gauge showing a low vacuum indicates that the system is not connected to the recovery path, or there's a blockage, with incomplete piercing being a common cause for new access points.
Why the other options are wrong
- A. An open purge valve on the recovery machine would draw in air, not prevent refrigerant flow from the appliance into the recovery system, and would likely impact the vacuum level differently.
- C. High ambient temperature would increase system pressure, potentially aiding flow, not preventing it.
- D. An overfilled recovery cylinder would prevent flow, but the system gauge would likely still show system pressure, not a low vacuum.
Piercing Valve Failure
If a piercing valve does not fully penetrate the refrigerant tubing, it will fail to establish an open pathway for refrigerant flow, preventing recovery.
- Common issue with new access points.
- Results in no refrigerant flow.
- System pressure will not equalize with recovery system pressure.
Memory trick: If the needle's not through, the flow won't ensue!