How to reduce the volumetric loss of a self-balancing multistage pump and improve operational efficiency?

The method and steps to reduce volumetric loss and improve operational efficiency of the Self-Balancing® multistage pump:

(1) Reduce leakage loss within the Self-Balancing multistage pump, improve the machining accuracy and assembly quality of parts, decrease the radial clearance between the balance disc front throttle sleeve and the impeller's front and rear sealing rings as well as the guide vane sealing rings, and reduce pressure energy loss caused by liquid leakage from the high-pressure side to the low-pressure side within the pump. Components such as the impeller sealing rings, guide vane sleeves, and balance disc front throttle should be made of materials with higher hardness and undergo heat treatment to enhance wear resistance.

(2) When starting a feedwater pump in cold state, it is required to warm the pump thoroughly according to regulations. If the warming is not sufficient, a large thermal difference can easily occur between the upper and lower parts of the pump body, causing the rotor to deform in an arch shape. Starting the pump at this time can easily cause internal sealing gaps to wear larger, leading to increased internal leakage and reflux volumetric loss.

(3) During operation, carefully monitor the axial movement of the pump and the changes in the balance disc rear water leakage pressure. When the balance disc rear water leakage pressure varies greatly over a wide range compared to the inlet pressure during normal operation, timely maintenance should be carried out to reduce leakage loss and improve the volumetric efficiency of the pump.

(4) Adjust the load smoothly to avoid significant fluctuations in feedwater pressure, maintain continuous and stable operation of the feedwater pump, reduce the axial movement of the pump to prevent wear on sealing gaps.