Disclosed is a water separator for continuous separation of water, air and particles. Separators of this type are used by dentists as well as in other areas such as water absorbers. The separator has an inlet pipe (18) for receipt of a mixture of water, air and particles simultaneously from several sources. The separator has a main tank (1) with an upper chamber (2) connected with a lower chamber (3) by a valve (17) in the bottom of the upper chamber. The lower chamber is normally closed by a check valve (8) in the bottom of the lower chamber. A three- way valve (24) located in an air connection pipe (20) is adapted to establish a connection between the upper and lower chambers in a first position. In a second position the valve closes the connection to the upper chamber and allows atmospheric air to enter into the lower chamber. The upper chamber has a coarse filter (4) capturing particles from the liquid flow to the lower chamber. The water separator has two tanks, the main tank (1) and a safety tank (11). The two tanks are connected through a connection pipe (19) from the upper chamber in the main tank to the safety tank and also connected through the air connection pipe from the lower chamber in the main tank to the safety tank. The inlet pipe goes through the lid of the main tank, and an outlet pipe (22) goes through the lid of the safety tank. The safety tank is normally closed by a check valve (15) in the bottom. The outlet pipe is connected to a suction motor (23).
