In general, how do the required recovery evacuation levels for Type III (low-pressure) appliances compare to those for Type II (high-pressure) appliances?
Not quite. The answer is B: Type III generally requires a notably deeper vacuum (lower absolute pressure) than Type II, since low-pressure equipment already operates near vacuum during normal operation
Table 1 of § 82.156 requires low-pressure appliances to be evacuated to 25 mm Hg absolute, which is a much deeper vacuum than the 0 to 15 inches of mercury vacuum required for high- and medium-pressure appliances. The relationship — Type III deeper than Type II — is the safe, exam-relevant fact; note that Type III is specified in mm Hg absolute rather than inches of mercury vacuum.
Reference: 40 CFR Part 82 § 82.156(a), Table 1 (Required levels of evacuation)
Checked against the official text
Read the eCFR text current through 2026-10-30 of § 82.156. Table 1: low-pressure appliances must be evacuated to 25 mm Hg absolute, a deeper vacuum than any high- or medium-pressure row (0 to 15 in. Hg vacuum).
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