A method of carrying out an integrity test function for a fluid circuit for blood component processing, the fluid circuit comprising at least one preformed, fluid pressure actuated pump station, at least one fluid flow path communicating with the pump station, and at least one valve in the fluid flow path, the fluid circuit being configured for interaction with a control module including an actuator to selectively apply fluid pressure to the pump station in concert with operation of the valve to pump fluid through the fluid flow path in response to a control program, the integrity test function comprising the steps of
- operating the control module to selectively apply pneumatic pressure to the pump station in concert with operation of the valve to introduce a fluid within a region of the fluid circuit,
- operating the control module to confine the fluid within the region while applying fluid pressure to the pump chamber, and
- generating an integrity output in response to sensing leakage of fluid from the region.