The pump type FN (OH1 vortex pump) is a single stage end suction pump with radially split case and vortex recessed impeller. It is designed to handle fluids containing large solids without clogging (up to the full diameter of the discharge); fragile solids, such as crystals, carbon and even live shellfish; abrasives; as well as long fibrous materials. The ideal solution for low shear applications. Mode of operation, the vortex impeller produces turbulence in the casing, which extends into suction pipe. As a result of this, a strong suction effect is imparted on the liquid-solid mixture. The centrifugal force caused by the turbulence transports the solids to the delivery branch within almost single revolution. The shape of the casing walls enables a high percentage of the solids to carried with air or gas. Since the fluid being handled does not flow through but alongside the open disc impeller, blockage is completely ruled out. The solids entrained with the liquid have hardly any contact with the impeller and are also not damaged in any other way.