Type III — Low-Pressure第 199 / 240 题
Which practice is correct when leak testing a low-pressure chiller that is under a vacuum?
a.Draw a deeper vacuum to reveal leaks
b.Vent refrigerant to lower the pressure
c.Add nitrogen and refrigerant to raise pressure above atmospheric, staying under 10 psig
d.Pressurize with oxygen to 15 psig
解析
To make a leak show outward, pressure must be raised above atmospheric, using nitrogen with a trace of refrigerant while staying at or below 10 psig. A deeper vacuum keeps leaks pulling air inward where a detector cannot sense them, venting is illegal, and oxygen is dangerous.
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同考点相关题目
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