What should be done before transferring refrigerant to an empty cylinder?

Transferring refrigerant to an empty cylinder requires that the cylinder be evacuated to remove any air and moisture. Evacuation creates a vacuum inside the cylinder, which not only ensures that no contaminants are present but also prevents reactions that can occur if moisture or air is introduced into the refrigeration system. By removing these contaminants, the integrity of the refrigerant stored in the cylinder is maintained, reducing the risk of harm to both equipment and the environment.

This process is essential because any leftover air or moisture can lead to the formation of acids or other byproducts that can damage the system when the refrigerant is used. Additionally, having a vacuum in the cylinder helps ensure that the refrigerant can be fully transferred without mixing with any unwanted substances. Proper evacuation is a critical step in handling refrigerants safely and effectively.