In a normally running system, what is in the suction line between the evaporator and the compressor?
Refrigeration · EPA 608 Core. The correct answer, and the reasoning behind it.
The refrigeration cycle, refrigerant states and pressures, gauges and leak detection.
The question
In a normally running system, what is in the suction line between the evaporator and the compressor?
- Low-pressure vaporCorrect answer
- High-pressure vapor
- High-pressure liquid
- Low-pressure liquid only
Why “Low-pressure vapor” is correct
Refrigerant leaving the evaporator has boiled off and is a low-pressure vapor, usually slightly superheated, as it returns to the compressor. Liquid reaching the compressor can damage it.
Source: EPA: Test Topics
Why the other answers are wrong
- High-pressure vapor — High-pressure vapor is in the discharge line after the compressor.
- High-pressure liquid — High-pressure liquid is in the liquid line after the condenser.
- Low-pressure liquid only — Liquid should have boiled off before leaving the evaporator.
Practice more of this
More EPA 608 Core 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.