Coast Guard Exams
Question 133Refrigeration/AC - QMED70% to pass

When opening or closing compressor service and line isolation valves on a typical refrigeration system that is fitted with packed valves, what must you do?

AI Explanation
The correct answer is A) you must first remove the stem seal cap. When opening or closing compressor service and line isolation valves on a typical refrigeration system that is fitted with packed valves, you must first remove the stem seal cap to access the packing gland. This allows you to properly tighten or loosen the packing gland to control the valve's seal and prevent leaks, without risking damage to the packing. The other answer choices are incorrect because: B) replacing the gasket each time is unnecessary, C) you should adjust the packing gland as needed, and D) turning the valves slowly is a good practice, but not the primary requirement.