Abstract: Caustic soda beads are transferred from a railcar to a receiving zone by means of an open loop air circuit. Ambient air is compressed in the circuit to a pressure of at least 75 psig in a compressor which simultaneously demoisturizes the air. Thereafter, the air is delivered to a dryer to be further demoisturized. The demoisturized, pressurized air is passed through a pressure reducing valve such that the air pressure is reduced to below 25 psig. A first portion of the low pressure air is conducted to the interior of the railcar. A second portion of the demoisturized, low pressure air is conducted through a control valve and then past an outlet of the railcar to cause caustic soda beads to become entrained therein and conducted to the receiving zone. The control valve is automatically adjusted in accordance with the pressure in the railcar to regulate the amount of pressurized air supplied to the railcar in order to maintain a constant pressure within the railcar.