EPA 608 609 - EPA Refrigerant Handling Type II High-Pressure Systems Questions and Answers 1 — Questions and Answers
Question 1: A technician is called to service a commercial refrigeration unit containing 60 pounds of R-404A. The annualized leak rate has been calculated to be 25%. According to EPA regulations, what is the required action?
- The leak must be repaired within 30 days. (Correct answer)
- The system must be immediately shut down and replaced.
- No action is required as the leak rate is below the threshold for commercial refrigeration.
- The owner has 12 months to monitor the leak before taking action.
Correct answer: The leak must be repaired within 30 days.
For commercial refrigeration appliances containing more than 50 pounds of refrigerant, the EPA has set a maximum allowable annual leak rate of 20%. Since the calculated leak rate of 25% exceeds this threshold, the owner or operator is required to have the leak repaired within 30 days of discovery.
Question 2: When recovering refrigerant from a Type II system with an inoperative compressor, which of the following is a correct procedure?
- Pressurize the system with nitrogen to force out the refrigerant.
- Use a passive (system-dependent) recovery device.
- Heat the compressor and strike it with a hammer.
- Recover as much liquid refrigerant as possible from the liquid line first. (Correct answer)
Correct answer: Recover as much liquid refrigerant as possible from the liquid line first.
To expedite the recovery process from any system, especially one with a non-operational compressor, it is most efficient to remove the refrigerant in its liquid state first. Recovering from the liquid line allows for the removal of the densest form of the refrigerant, significantly speeding up the overall recovery time before recovering the remaining vapor.
Question 3: A technician needs to perform a major repair on a high-pressure appliance containing 210 lbs of R-22 that was manufactured after November 15, 1993. What is the required evacuation level?
- 0 inches of Hg
- 4 inches of Hg
- 15 inches of Hg
- 10 inches of Hg (Correct answer)
Correct answer: 10 inches of Hg
For high-pressure appliances containing 200 pounds or more of refrigerant, and when using recovery/recycling equipment manufactured after November 15, 1993, the EPA requires evacuation to a level of 10 inches of Hg vacuum.
Question 4: Which of the following safety precautions is critical when pressurizing a Type II system with nitrogen for a leak test?
- Use a small amount of oxygen as a trace gas.
- Pressurize the system to at least 500 psig to find all leaks.
- Ensure a pressure regulator and a pressure relief valve are installed on the nitrogen cylinder. (Correct answer)
- Always charge the nitrogen as a liquid to speed up the process.
Correct answer: Ensure a pressure regulator and a pressure relief valve are installed on the nitrogen cylinder.
When using nitrogen to pressurize a system for leak testing, it is essential to use a pressure regulator to control the pressure being introduced into the system and a pressure relief valve as a safety backup to prevent over-pressurization, which could cause a rupture or explosion.
Question 5: A technician is disposing of a high-pressure appliance containing more than 5 pounds but less than 50 pounds of R-134a. What must be done before the appliance can be scrapped?
- The refrigerant must be vented in a well-ventilated outdoor area.
- The refrigerant must be recovered to a level of 4 inches of Hg vacuum.
- Records of the refrigerant recovery must be kept for at least 3 years. (Correct answer)
- The compressor must be rendered inoperative.
Correct answer: Records of the refrigerant recovery must be kept for at least 3 years.
The EPA requires that for the disposal of appliances containing between 5 and 50 pounds of refrigerant, the technician must keep records of the disposal. These records typically include the location, date of disposal, and the type of refrigerant recovered. These records must be maintained for a minimum of three years.
Question 6: When charging a blended refrigerant like R-410A into a Type II system, how should the refrigerant be introduced?
- As a vapor through the suction line with the system running.
- As a liquid into the king valve or liquid line service port. (Correct answer)
- It can be charged as either a liquid or vapor depending on ambient temperature.
- As a throttled liquid into the compressor's suction port.
Correct answer: As a liquid into the king valve or liquid line service port.
Blended refrigerants, such as those in the 400-series like R-410A, must be charged as a liquid to prevent fractionation. Fractionation is the separation of the different components of the blend, which would alter the refrigerant's properties and impair system performance. Charging as a liquid ensures the correct mixture enters the system.
