What does the rule require before the valve is opened?

Recovery requirements · EPA 608 Type III. The correct answer, and the reasoning behind it.

Evacuation levels for low-pressure appliances, and major versus non-major repairs.

The question

A technician will replace a small valve on an R-11 chiller, uncovering about 1.5 square inches for 10 minutes. The chiller will not be evacuated to the atmosphere afterward. What does the rule require before the valve is opened?

• AEvacuate the chiller to 15 inches of Hg vacuum
• BPressurize the chiller to 10 psig with nitrogen
• CPressurize the chiller to no higher than 0 psigCorrect answer
• DEvacuate the chiller to 4 inches of Hg vacuum

Why “Pressurize the chiller to no higher than 0 psig” is correct

For a non-major repair that is not followed by evacuation to the atmosphere, 40 CFR 82.156(a)(1)(ii) lets a low-pressure appliance be opened once it is pressurized to no higher than 0 psig. Bringing the pressure up to atmosphere keeps air and moisture from rushing in and refrigerant from rushing out when the valve is opened.

Source: 40 CFR 82.156(a)(1)(ii); 40 CFR 82.152

Why the other answers are wrong

• Evacuate the chiller to 15 inches of Hg vacuum — 15 inches of Hg vacuum is a medium-pressure level and is not the non-major repair rule for low-pressure appliances.
• Pressurize the chiller to 10 psig with nitrogen — The goal is 0 psig, and R-11 chillers may not use nitrogen or other methods that require later purging.
• Evacuate the chiller to 4 inches of Hg vacuum — 4 inches of Hg vacuum is a pre-1993 level for higher-pressure appliances, not the low-pressure non-major rule.

Practice more of this

More EPA 608 Type III practice questions, or see every EPA 608 practice test.