The Becker Pumps Australia have three main types of Dental Suction Systems that are used by Dental Surgeries, Dental Hospitals and Training Facilities;

• Dry (line) Suction System; this system removes solids and liquids within the surgery leaving the pipeline from the separator to the suction pump dry.
• Semi-Dry (line) Suction System; this system removes solids from one or a number of surgeries at a central collection point adjacent to the surgery or surgeries.  The pipeline from the separator to the suction pump is dry.
• Wet (line) Suction System; this system discharges to waste solids less than 600mm mesh size and liquids through a "wet" pipeline via a suction pump.

All of the Dental Suction System are fitted with a Becker Side Channel Vacuum Pump.  Whilst the pumps that used have maximum pressure greater than required in dental suction, the pumps are fitted with relief valves to vent and maintain the systems automatically at a gauge pressure of not more than -20 kPa.

For more detail: http://www.beckerpumps.com.au/dental-suction-systems.html