Methods and steps of self balancing multi-stage pump to reduce volume loss to improve operation efficiency:
(1) It can reduce the leakage loss in multistage pump, improve the machining accuracy and assembly quality of parts, reduce the radial clearance of throttling sleeve in front of equalizing disc, the radial clearance of sealing ring before and after impeller and guide vane seal ring, and reduce the pressure energy loss caused by liquid leakage from high pressure side to low pressure side. The materials with higher hardness should be selected for the sealing ring of impeller, guide vane sleeve and throttling in front of equalizing disc, and the heat treatment for improving wear resistance shall be stopped.
(2) When starting the feed water pump in cold state, it is required to warm up the pump according to the regulations. If the warm-up pump is not sufficient, large thermal temperature difference between the upper and lower parts of the pump body is easy to cause bow deformation of the rotor. At this time, starting the multi-stage centrifugal pump can easily make the internal sealing gap larger, form internal leakage and increase the loss of reflux volume.
(3) During the operation, the axial movement of the pump and the change of the discharge pressure after the equalizing plate shall be carefully monitored. During normal operation, when the discharge pressure after the equalizing plate changes greatly than the inlet pressure of the pump, timely maintenance shall be carried out to reduce the leakage loss and improve the volumetric efficiency of multistage pumps.
(4) When adjusting the load, it should be stable to prevent the water supply pressure from being shaken greatly, adhere to the continuous and stable operation of the feed pump, reduce the axial movement of the pump, so as to avoid the formation of seal clearance wear.