Concepts and their limits
The limited exception for a non-major repair not followed by evacuation to the environment requires high- or very-high-pressure equipment to reach 0 psig before opening. When leaks prevent normal evacuation without substantial contamination, isolate where possible, fully evacuate non-leaking parts, and evacuate leaking parts to the lowest attainable level not above 0 psig. Oil can contain dissolved refrigerant. Before an oil change, reduce the applicable appliance/isolated portion or receiving system to no more than 5 psig. Applicable recovery equipment must meet certified standards; AHRI and UL are approved testing organizations. The equipment certification label is distinct from a technician credential.
Worked decisions
A stated non-major high-pressure repair will not be followed by evacuation to the environment. What pressure is required before opening under this limited exception? The decision is 0 psig. The limited exception for a non-major repair not followed by evacuation to the environment requires high- or very-high-pressure equipment to reach 0 psig before opening. A leak prevents a normal evacuation target without substantial contamination. Which first planning step is appropriate where possible? The decision is Isolate leaking components from non-leaking components. When leaks prevent normal evacuation without substantial contamination, isolate where possible, fully evacuate non-leaking parts, and evacuate leaking parts to the lowest attainable level not above 0 psig. An oil-change plan reports pressure of 3 psig before oil removal. With all other stated conditions met, does it satisfy the no-greater-than 5 psig condition? The decision is Yes; 3 psig is below the ceiling. Oil can contain dissolved refrigerant. Before an oil change, reduce the applicable appliance/isolated portion or receiving system to no more than 5 psig. A recovery machine bears the applicable AHRI/UL certification statement for its appliance category. What does that label concern? The decision is Equipment performance certification. Applicable recovery equipment must meet certified standards; AHRI and UL are approved testing organizations. The equipment certification label is distinct from a technician credential.
Contrasts that change the decision
A technician invokes the limited non-major-repair exception but plans a major repair. Which prerequisite is missing? Here the supported answer is The repair must actually be non-major. The limited exception for a non-major repair not followed by evacuation to the environment requires high- or very-high-pressure equipment to reach 0 psig before opening. A leaking component is isolated from sound components. What is required for the non-leaking part? Here the supported answer is Evacuate it to the specified applicable level. When leaks prevent normal evacuation without substantial contamination, isolate where possible, fully evacuate non-leaking parts, and evacuate leaking parts to the lowest attainable level not above 0 psig. An oil-change plan reports pressure of 5 psig before oil removal. With all other stated conditions met, does it satisfy the no-greater-than 5 psig condition? Here the supported answer is Yes; 5 psig is at the allowed ceiling. Oil can contain dissolved refrigerant. Before an oil change, reduce the applicable appliance/isolated portion or receiving system to no more than 5 psig. A service company buys a certified recovery machine. What qualification is not automatically obtained by that purchase? Here the supported answer is The technician's required personal certification. Applicable recovery equipment must meet certified standards; AHRI and UL are approved testing organizations. The equipment certification label is distinct from a technician credential.
Transfer and self-check
An oil change is planned at 7 psig. What pressure condition is not met? 7 is greater than the no-more-than 5 psig ceiling. The technician must address that condition rather than assuming every pressure below normal operation is acceptable.
A stated non-major high-pressure repair will not be followed by evacuation to the environment. What pressure is required before opening under this limited exception?
- The relevant stated condition is: A stated non-major high-pressure repair will not be followed by evacuation to the environment.
- Apply the relevant source rule. The limited exception for a non-major repair not followed by evacuation to the environment requires high- or very-high-pressure equipment to reach 0 psig before opening.
- This supports “0 psig”. The alternative “5 psig” uses a different condition or conclusion;the applicable rule above explains why it does not answer this case.
Compare the other answer choices
This choice (5 psig) does not fit the stated conditions. The limited exception for a non-major repair not followed by evacuation to the environment requires high- or very-high-pressure equipment to reach 0 psig before opening.
This choice (10 psig) does not fit the stated conditions. The limited exception for a non-major repair not followed by evacuation to the environment requires high- or very-high-pressure equipment to reach 0 psig before opening.
This choice (Normal operating pressure) does not fit the stated conditions. The limited exception for a non-major repair not followed by evacuation to the environment requires high- or very-high-pressure equipment to reach 0 psig before opening.
Try it, then explain it.
Complete a short set without looking at the example. After each answer, explain which evidence or rule supports your decision and why the alternatives do not fit.
Sources & authorship
Original Slope explanations and examples. References support the concepts; they are not the source of copied questions. Independent educator review is pending.
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