Pump

In a reciprocating piston pump for pumping fluids which contain a high degree of suspended particles including a cylinder having a fluid inlet and a fluid outlet and a piston movable within said cylinder for pumping fluid from said fluid inlet to said fluid outlet, the improvement which comprises a hollow elongated metal piston having an exterior peripheral surface and a valve, a cylinder having an interior surface, a first cylindrical sleeve mounted over the exterior peripheral surface of said piston and a second cylindrical sleeve lining the interior surface of the cylinder wherein said first cylindrical sleeve and said second cylindrical sleeve are made of a hard ceramic material having a hardness of greater than nine on the Mho scale such that any suspended particles which lodge between said first cylindrical sleeve and said second cylindrical sleeve are pulverized as said piston moves within said cylinder.