Pressure gene­ration is achieved through two series connected stages. The unit is equipped with vibration isolation and a silenced enclosure. The unit should always be equipped with an exhaust silencer (inlet also if required). The unit is direct driven and has minimal service requirements (lubrication interval 10000 hours).

RAF 2503 developes a maximum negative pressure of 20 kPa. Note though that the maximum airflow is 2800 m3/h. Above this, the power consumption would be too large for the 30 kW motor, so the design of the system must throttle to this level for all cases.