A positive airway pressure, PAP, device for delivery of respiratory therapy to a patient, the PAP device comprising a casing and a blower provided within the casing, the blower comprising: a blower housing (20, 25) including an inlet and an outlet; a motor to drive a rotatable shaft; second and third impellers provided to the shaft, the second and third impellers each including a plurality of impeller blades; and a first impeller positioned upstream of the second impeller; a second stationary component provided to the blower housing (20, 25) and including stator vanes (85-1, 85-2) downstream of the second impeller; a third stationary component provided to the blower housing (20, 25) and including stator vanes downstream of the third impeller; a first stationary component provided to the blower housing (20, 25) and including stator vanes following the first impeller, the first stationary component being positioned upstream of the second impeller, the third and first stationary components being similar to one another, wherein a first set of stator vanes (85-1, 85-2) of the second stationary component is provided around the motor and is configured and arranged to direct airflow along the motor, to de-swirl the airflow and decelerate air to increase pressure; wherein each of the third and first stationary components includes: a respective shield providing a respective first set of stator vanes; and a respective stationary component housing providing a respective second set of stator vanes, the shield assembled to the stationary component housing to provide a respective full set of stator vanes including both the respective first and second sets of stator vanes; wherein vane passages each structured to provide an expanding passage to increase pressure are defined between adjacent stator vanes of each full set of stator vanes. a blower housing (20, 25) including an inlet and an outlet; a motor to drive a rotatable shaft; second and third impellers provided to the shaft, the second and third impellers each including a plurality of impeller blades; and a first impeller positioned upstream of the second impeller; a second stationary component provided to the blower housing (20, 25) and including stator vanes (85-1, 85-2) downstream of the second impeller; a third stationary component provided to the blower housing (20, 25) and including stator vanes downstream of the third impeller; a first stationary component provided to the blower housing (20, 25) and including stator vanes following the first impeller, the first stationary component being positioned upstream of the second impeller, the third and first stationary components being similar to one another, wherein a first set of stator vanes (85-1, 85-2) of the second stationary component is provided around the motor and is configured and arranged to direct airflow along the motor, to de-swirl the airflow and decelerate air to increase pressure; wherein each of the third and first stationary components includes: a respective shield providing a respective first set of stator vanes; and a respective stationary component housing providing a respective second set of stator vanes, the shield assembled to the stationary component housing to provide a respective full set of stator vanes including both the respective first and second sets of stator vanes; a respective shield providing a respective first set of stator vanes; and a respective stationary component housing providing a respective second set of stator vanes, the shield assembled to the stationary component housing to provide a respective full set of stator vanes including both the respective first and second sets of stator vanes; wherein vane passages each structured to provide an expanding passage to increase pressure are defined between adjacent stator vanes of each full set of stator vanes.