What action is specified before receiving refrigerant into a cylinder?

What action is specified before receiving refrigerant into a cylinder?

• A. The cylinder should be warmed
• B. The cylinder should be filled with nitrogen
• C. The cylinder should be evacuated
• D. The cylinder should be weighed

Answer: (C)

Evacuating the cylinder is the step used to prepare it for charging with refrigerant. By pulling a deep vacuum, you remove air and moisture that could contaminate the refrigerant, cause acids, or create non‑condensables that skew charge accuracy and system performance. This creates a clean, dry environment so the refrigerant can be weighed and charged more reliably. Warming the cylinder isn’t required and can increase pressure or risk, while purging with nitrogen is a separate procedure used in some cases to purge lines, not the essential pre-charge step for the cylinder itself. Weighing the cylinder comes into play after charging to verify the correct amount has been added.

Evacuating the cylinder is the step used to prepare it for charging with refrigerant. By pulling a deep vacuum, you remove air and moisture that could contaminate the refrigerant, cause acids, or create non‑condensables that skew charge accuracy and system performance. This creates a clean, dry environment so the refrigerant can be weighed and charged more reliably.

Warming the cylinder isn’t required and can increase pressure or risk, while purging with nitrogen is a separate procedure used in some cases to purge lines, not the essential pre-charge step for the cylinder itself. Weighing the cylinder comes into play after charging to verify the correct amount has been added.