A technician must bring an R-113 machine up to atmospheric pressure for a non-major repair. Which procedure…

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 must bring an R-113 machine up to atmospheric pressure for a non-major repair. Which procedure follows 40 CFR 82.156(a)(1)(ii)?

• AUse nitrogen alone, since R-113 is exempt from the heat requirement
• BUse heat only, because nitrogen is never allowed on low-pressure machines
• CUse compressed air to reach atmospheric, then purge before opening
• DHeat it as far as heat will go, then add nitrogen up to atmosphericCorrect answer

Why “Heat it as far as heat will go, then add nitrogen up to atmospheric” is correct

For low-pressure refrigerants that boil above 85 °F at atmospheric pressure, such as R-113, the rule requires heat to raise internal pressure as much as possible. Nitrogen may then be used only to bring the pressure from that point up to atmospheric.

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

Why the other answers are wrong

• Use nitrogen alone, since R-113 is exempt from the heat requirement — Heat must be used first, as much as possible, before any nitrogen is added.
• Use heat only, because nitrogen is never allowed on low-pressure machines — Nitrogen is allowed on R-113 machines to make up the last of the pressure after heat.
• Use compressed air to reach atmospheric, then purge before opening — Air is not an allowed method and would contaminate the refrigerant.

Practice more of this

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