Pump casting process is grey cavity cast iron, high carbon content, close to co-crystalline components, so melting point is relatively low, good fluidity, low shrinkage rate, so suitable for casting structures complicated or thin wall castings. Pump casting process is grey cavity cast iron, high carbon content, close to co-crystalline components, so melting point is relatively low, good fluidity, low shrinkage rate, so suitable for casting structures complicated or thin wall casti