Coast Guard Exams
Question 8Refrigeration/AC - QMED70% to pass

With a service gauge manifold set connected to a refrigerant compressor as shown in the illustration, which arrangement of the gauge manifold set valves and compressor service valves would allow for simultaneous reading of the compressor suction and discharge pressures? Illustration GS-RA-03

AI Explanation
The correct answer is B) Valves "2" and "5" both closed, along with valves "1" and "6" both cracked open off their backseats. This arrangement allows for simultaneous reading of the compressor suction and discharge pressures. With valves "2" and "5" closed, the gauge manifold set is isolated from the refrigerant system, but with valves "1" and "6" cracked open, the suction and discharge pressures can be read directly from the gauge manifold. The other options are incorrect because they either do not isolate the gauge manifold set from the system (A and C) or do not allow for pressure readings to be taken (D).