A water separator is an important part of a compressor, as it helps to remove water from the air before it enters the compressor. This is important because water can damage the compressor, and it can also cause problems with the air pressure. To use a water separator, you will need to connect it to the compressor. Once it is connected, the separator will work automatically to remove water from the air. You may need to empty the water from the separator occasionally, but it will help to prolong the life of your compressor.