The air tank allows compressed air systems to operate more efficiently and to balance demand fluctuations in the system pressure. Air tanks store the amount of air required to meet sudden air demands that exceed compressor capacity. Another benefit of the air tank is that it facilitates the condensation of the air in the air and the emptying of the resulting condensate. The water that accumulates as a result of the condensation in the air tank is discharged to the outside. In this way the air in the system becomes dry.