Type II — High-PressureCâu 137 / 240
A technician plans to retrofit an old R-22 system to an HFC blend that uses polyolester (POE) oil. Which statement about the retrofit is correct?
a.Mineral oil works with all HFC blends, so no oil change is needed
b.The R-22 must be recovered, and the mineral oil is typically replaced with the POE oil the new refrigerant requires
c.Retrofitting removes the need for any leak repair
d.The remaining R-22 can be vented since the system is being changed
Giải thích
In a retrofit, the existing R-22 must be recovered, never vented, and because most HFC blends are not compatible with mineral oil, the oil is usually changed to polyolester (POE). Components like the filter-drier are commonly replaced and the metering device may need adjustment. Venting during a retrofit is prohibited under Section 608.
Trích dẫn luật: 40 CFR §82.154Luyện miễn phí toàn bộ 240 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A technician needs to locate a small refrigerant leak on an R-22 condensing unit. Which method is a recognized leak-detection technique?
- A technician pressure-tests a repaired R-410A system for leaks before evacuating. Which gas is appropriate for pressurizing the system for a leak test?
- A technician notices R-410A gauge pressures running much higher than an equivalent R-22 system at the same conditions. What does this reflect about R-410A?
- A technician handles a high-pressure refrigerant cylinder in a hot truck bed in summer. Which practice is safest for storing and transporting the cylinder?
- A technician sets up push-pull recovery on a system with a large liquid charge. How does the push-pull method work?
- A very-high-pressure appliance using R-13 must have its refrigerant recovered before service. Using recovery equipment made after November 15, 1993, what is the required evacuation level?
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