🔍 Key Concepts

• Refrigeration charging procedures on marine systems • How to remove air and moisture from hoses before connecting to the system • Why contaminants (air, moisture, solvents, oil) are dangerous to a refrigeration plant

💭 Think About

• Which one of these preparations would help ensure that no air or non‑condensable gases are introduced into the system through the hoses? • Which option could add unwanted contaminants (like solvent or excess oil) into the refrigeration system, and why is that a problem? • On a practical shipboard job, what simple step do mechanics take with the manifold hoses right before opening the valves to the system?

✅ Before You Answer

• Eliminate any choice that would introduce foreign chemicals or solvents into the system that are not refrigerant itself • Consider which method is actually taught and used in standard charging practice with manifold gauges and hoses • Think about the goal: the hoses should contain only refrigerant, not air, moisture, or cleaning agents, when you start charging