The seal is protected in two ways. The conical shape of the seal chamber allows the accumulated
air to be naturally discharged towards the pump outlet. Thanks to this technical solution, the pumped fluid always gets in contact with the seal to lubricate or cool it. The helical groove discharges sludge and solid particles from the seal to the pump outlet in a simple way. The rear part of the impeller or the follower rotates and imparts a proportion of its kinetic energy to the liquid present in the sealing chamber. The helical groove is oriented so that the impurities are transported towards the pump outlet by rotating liquid. In this way, the abrasive action of impurities on the sealing faces of the mechanical seal is eliminated and their service life is significantly extended.