Why should liquid refrigerant never be trapped in a hose or line between two closed valves?
Safety · EPA 608 Type II. The correct answer, and the reasoning behind it.
Hermetic compressors under vacuum and other high-pressure hazards.
The question
Why should liquid refrigerant never be trapped in a hose or line between two closed valves?
- The liquid will turn into oil
- It makes recovery machines lose certification
- Warming liquid expands and can burst the lineCorrect answer
- It changes the refrigerant's pressure class
Why “Warming liquid expands and can burst the line” is correct
Liquid refrigerant expands as it warms. With no vapor space to absorb the expansion, pressure in a liquid-full section rises sharply and can rupture a hose or line.
Source: EPA: Test Topics
Why the other answers are wrong
- The liquid will turn into oil — Refrigerant does not change into oil.
- It makes recovery machines lose certification — Equipment certification has nothing to do with trapped liquid.
- It changes the refrigerant's pressure class — Pressure class depends on the refrigerant, not on where it is trapped.
Practice more of this
More EPA 608 Type II practice questions, or see every EPA 608 practice test.
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.