The part on a slurry tanker that does the most amount of work and is subject to the most wear and tear is undoubtedly the vacuum pump. It works on the principle of removing the air from the tank which creates a vacuum which in turn sucks up the slurry. The pump is also used in reverse to push air back into the tank creating pressure which will spread the liquid once the gate valve is opened.The vacuum pump normally used is a rotary vane pump which consists of vanes mounted into a rotor that rotates inside of a cavity or chamber. The centres of the two rotor ends are offset, causing eccentricity. The vanes are allowed to slide in and out of the rotor and seal against the edges which creates vane chambers that do the pumping work. Over time especially if not maintained correctly the vanes inside the pump can wear, break or become stuck inside the rotor slots which will drastically reduce the pumps ability to work efficiently and often stop it working altogether.