Question 195Refrigeration & AC - Assistant Engineer

The correct answer is D) Closing the valve labeled "G" isolates the hose labeled "H" from the hose labeled "J". This is correct because the valve labeled "G" acts as an isolation valve, allowing the user to isolate the hose labeled "H" from the hose labeled "J" when closed. This is a common function of gauge manifold sets, to allow for the isolation of individual components for testing or maintenance purposes. The other answer choices are incorrect because: A) Opening both valves "G" and "C" is not necessary to read the system pressures on the respective gauges. B) Closing valve "G" does not isolate the hose "H" from the gauge "A", it isolates it from the hose "J". C) Fully opening and back seating valve "G" does not isolate the gauge "A" from the hose "H", closing the valve does.