To what level must the chiller be evacuated first?

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 using a recovery machine built in 2019 is about to open an R-123 centrifugal chiller to replace the compressor. To what level must the chiller be evacuated first?

• A10 inches of Hg vacuum
• B25 mm Hg absoluteCorrect answer
• C15 inches of Hg vacuum
• D0 psig

Why “25 mm Hg absolute” is correct

Table 1 in 40 CFR 82.156(a) sets one level for every low-pressure appliance: 25 mm Hg absolute. Replacing the compressor is a major repair, so the full Table 1 level applies before the chiller is opened.

Source: 40 CFR 82.156(a), Table 1

Why the other answers are wrong

• 10 inches of Hg vacuum — 10 inches of Hg vacuum is a Table 1 level for some medium- and high-pressure appliances, not low-pressure ones.
• 15 inches of Hg vacuum — 15 inches of Hg vacuum applies to medium-pressure appliances with 200 pounds or more; a low-pressure chiller must go much deeper.
• 0 psig — 0 psig is far too shallow for a major repair on a low-pressure appliance.

Practice more of this

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