Published at Saturday, August 25th 2018, 07:18:58 AM by Gay Jennings. Air Compressor. Compression not only produces heat but squeezes water out of the air which ends up in the tank. Tanks can rust internally over time and if this is not controlled, the rusted air tank can eventually explode causing considerable damage and even death. That is why it is really important to evacuate the tank of water regularly. Most air compressors come equipped with a drain valve at the lowest point of the tank. If you dont want to spray water all over the floor under the unit, you may want to consider piping it from the valve to another place such as under the floor or into a drain. Piped water will flow uphill into a sink because it is being pushed out of the tank by compressed air.