These filtres retain impurities and liquids extracted through vacuum cups or vacuum clamping systems, preventing them from entering into the vacuum pumps. They are composed of:

- A transparent plexiglas cylindrical container with an extractable lid to allow inspection

and cleaning.

- A check valve located on the suction inlet for preventing the air from returning in the filtre when the pump is idle.

- A stainless steel mesh filtering cartridge with a filtering degree equal to 44 μ, also located on the suction inlet to retain dust and solid impurities.

- A 2-way manual valve for service vacuum interception.

- A 2-way manual valve for restoring the atmospheric pressure inside the filtre.

- A radial vacuum gauge the direct reading of the vacuum level.

- A magnetic level switch that stops the pump when the sucked liquid exceeds the safety level. - A rigid pipe connected to the service to convey the air flow and the sucked liquid to the bottom of the container.

- A check valve at the bottom of the filtre to automatically drain the sucked liquid and impurities every time the atmospheric pressure is restored inside the filtre.

- A cock applied on the aforementioned check valve for manual liquid drainage.

- A sturdy metal bracket for fixing the filtre to the wall.