To what pressure must the system, or the isolated portion, be brought before the oil is removed?

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

Evacuation levels by charge size and equipment date, major repairs, and system-dependent limits.

The question

A technician needs to change the compressor oil in a 90-pound R-22 system. To what pressure must the system, or the isolated portion, be brought before the oil is removed?

• ANo higher than 0 psig
• BNo higher than 15 psig
• CNo higher than 10 inches of Hg vacuum
• DNo higher than 5 psigCorrect answer

Why “No higher than 5 psig” is correct

For oil changes, the appliance must be evacuated or pressurized to no higher than 5 psig before it is opened, or the oil can be drained into a system receiver brought to that level. Oil holds dissolved refrigerant, so the pressure drop releases it for recovery.

Source: 40 CFR 82.156(a)(1)(iii); EPA: Service Practice Requirements

Why the other answers are wrong

• No higher than 0 psig — 0 psig is the level for non-major repairs; oil changes have their own 5 psig limit.
• No higher than 15 psig — 15 psig is above the allowed limit; EPA calls oil changes above 5 psig a violation.
• No higher than 10 inches of Hg vacuum — 10 inches is a Table 1 level, not the oil-change requirement.

Practice more of this

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