How does the required evacuation level for disposing of an R-123 chiller compare with the level for a major repair on the same chiller?
25 mm Hg absolute, the same as for a major repair. Table 1 gives low-pressure appliances a single level, whatever the equipment date.
- Disposal is stricter: 500 microns
- Disposal is looser: 0 psig
- They are the same: 25 mm Hg absoluteCorrect answer
- Disposal is looser: 10 inches of Hg vacuum
Why “They are the same: 25 mm Hg absolute” is correct
40 CFR 82.156(a) applies Table 1 both before opening an appliance and before disposing of it. Table 1 gives low-pressure appliances a single level, 25 mm Hg absolute, so disposal and a major repair share the same target unless leaks make it unattainable.
Source: 40 CFR 82.156(a); 40 CFR 82.156(a), Table 1
Why the other answers are wrong
- Disposal is stricter: 500 microns — 500 microns is a common dehydration target, not the Table 1 disposal level.
- Disposal is looser: 0 psig — Disposal is not relaxed to 0 psig for a non-leaking low-pressure appliance.
- Disposal is looser: 10 inches of Hg vacuum — 10 inches of Hg vacuum is not the low-pressure level for any situation in Table 1.
The source, word for word
Low-pressure appliance 25 mm Hg absolute 25 mm Hg absolute.
Evacuate leaking components to be opened or disposed of to the lowest level that can be attained without substantially contaminating the refrigerant. This level may not exceed 0 psig.
When the level changes
Table 1 applies both before opening an appliance and before disposing of it. These are the exceptions.
| Situation | Required level |
|---|---|
| Disposal or major repair | 25 mm Hg absolute |
| Leaking components, where 25 mm would badly contaminate the refrigerant | The lowest level attainable, never above 0 psig |
| Non-major repair not followed by evacuation to the atmosphere | Pressurized to no higher than 0 psig |
| Oil change | No higher than 5 psig |
Reading the number
Absolute pressure is measured from a perfect vacuum, not from atmospheric pressure, so 25 mm Hg absolute is roughly 29 inches of Hg vacuum on a standard gauge. After reaching it, wait and watch for the pressure to rise.
Keep practicing
- EPA refrigerant recovery rules
- Why pressure rises after reaching recovery vacuum
- What the venting ban requires at disposal
- EPA 608 Type 3 practice test
- EPA 608 Type 3 mock exam
Unofficial, not affiliated with the EPA or any EPA-approved certifying organization. Questions are original practice written from public EPA material, not real exam questions.