What must be done before connecting an oil charging line to a compressor?

Before connecting an oil charging line to a compressor, it is essential to purge the line of air. This step is critical to ensure that the oil being introduced into the system does not mix with any air or contaminants. Air in the oil charging line can lead to the formation of bubbles, which can cause operational inefficiencies, foaming, and may even result in damage to the compressor components. Additionally, preventing the introduction of air helps maintain the integrity of the oil and supports proper lubrication, which is vital for the compressor's optimal functioning.

Purging the line typically involves using an inert gas, like nitrogen, to push out the air, ensuring that only oil will flow into the compressor. This practice is an important part of good maintenance procedures within refrigeration systems, promoting reliability and efficiency.