(1) Motor reversal
(2) Deviation of operating point towards high flow and low head
(3) Speed reduction
(4) Cavitation occurs at the entrance
(5) Internal leakage occurs
When the clearance between the rotating and stationary parts inside the pump exceeds the design range, it will cause internal leakage, manifested as a decrease in the discharge pressure of the pump, such as the clearance between the impeller mouth ring and the inter stage clearance of multi-stage pumps. At this time, corresponding disassembly and inspection should be carried out to repair or replace the parts that cause excessive clearance.
(6) Impeller flow channel blockage
