... of urban construction, factory and mine.PrincipleYou should fill the pump with water before start, then the impeller rotate with ... head overtop3,drop itbearing heating1,grease too much or not enough1,increase or decrease properly2,pump shaft bended2,adjust or replace3 ... shaft power increased1,the rotate speed is too high1,adjust2,pump shaft bended2,adjust or replace3,bearing wear seriously3,replace ...