Abstract: A pneumatic transport system, particularly useful as a mail transport system, which includes a transport carrier moving through a pneumatic tube line between remote sending/receiving stations is described. Movement of the transport carrier through the pneumatic tube line is by means of a positive or negative air flow in the tube line provided by a blower means. The air flow direction is controlled by utilizing a series of adjustable valves, such as butterfly valves. The system additionally employs sensors for indicating the presence of the carrier in the exterior station.