A centrifugal blood processing apparatus comprising a centrifuge rotor, a separation chamber, a tubing set for conducting blood components and fluids and having an inlet line, an outlet line and a storage solution line in fluid communication with the outlet line at a junction. The apparatus controls pumps to conduct a predetermined quantity of storage solution to a collected blood component. The apparatus also purges blood components in the tubing set by applying a negative pressure and positive pressure. A disposable blood processing set has a separation chamber; a tubing set including an inlet line in fluid and an outlet and a storage solution line connected to the outlet line at a junction.