The pump casing of the slurry pump is usually cast into a volute shape, and its water passage requires good hydraulic conditions. When the impeller is working, the flow rate gradually increases along the gradually expanding section of the volute. In order to reduce hydraulic losses, the water flow speed along the gradually expanding section of the volute should be kept constant in pump design. After being discharged from the volute, water flows into the pressure pipe through a conical diffusion tube. The function of the conical diffusion tube on the volute is to lower the velocity of the water flow, converting a portion of the velocity head into a pressure head.
The material selection of the pump casing should not only consider the corrosion and wear of the medium on the overflow part, but also ensure that the casing has sufficient mechanical strength as a pressure vessel.