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By improving the geometry of the impeller inlet, once the pump’s speed and flow rate are determined, the pump’s net positive suction head is solely dependent on the geometry of the suction chamber and the impeller inlet. Therefore, one of the main measures to improve the cavitation resistance of water pumps is to modify the geometry at the inlet of the impeller. (1) By using a lower impeller inlet velocity and increasing the impeller inlet diameter, the impeller inlet velocity can be reduced, thereby improving the pump’s cavitation resistance; however, the pump’s hydraulic efficiency decreases. (2) Increasing the width of the blade inlet edge can reduce the relative velocity at the impeller inlet, thereby improving the cavitation performance of the pump. (3) Curvature radius of the inlet section of the impeller cover: Due to the effect of centrifugal force on the fluid flowing at the impeller inlet as it turns, the pressure is low and the flow velocity is high near the front cover, resulting in an uneven velocity distribution at the impeller inlet. Appropriately increasing the radius of curvature of the cover plate helps to reduce the front cover plate and improve the uniformity of the velocity distribution, as well as to decrease the pressure drop in the pump inlet section. This results in a lower NPSHr and enhances the pump’s cavitation resistance. (4) Position of the blade inlet edge and shape of the blade inlet section: Extending the blade inlet edge appropriately in the direction of the suction port allows the liquid to be affected by the blade earlier, increases the blade’s surface area, and reduces the pressure difference between the working surface and the back side of the blade. Furthermore, the forward extension of the blade reduces the radius at the inlet edge, thereby reducing the pressure drop. But. After the blades are extended forward, they need to be made very thin; otherwise, there will be severe crowding. The inlet edge of the blade is inclined, resulting in varying circumferential pressure differences at different points. Generally, the axial velocity is approximately uniformly distributed along the inlet edge, so the relative flow angle at different points on the inlet edge varies. To accommodate this flow pattern and reduce shock losses, the inlet edge of the blade should be shaped with spatial distortion. This is the principle behind why, at present, the inlet sections of many impeller blades with low specific speed are also designed as twisted blades. (5) Blade inlet chamfer: The blade inlet chamfer is usually greater than the relative flow angle at the inlet, that is, β1 > β’1, and the positive chamfer value △β = β1 – β’1; the value of this chamfer is typically between 3° and 10°, with some cases reaching up to 15°. Using a positive attack angle can improve cavitation resistance with little impact on efficiency, for the following reasons: 1) It increases the blade inlet angle β1, thereby reducing blade bending, increasing the flow area at the blade inlet, and reducing blade crowding. All these factors will reduce the crowding of the blades. All these factors will reduce the pressure drop and improve the cavitation resistance of the pump ； 2) By using a positive attack angle, at the design flow rate, separation occurs on the back side of the blade inlet. Since the back side is the low-pressure side of the flow channels between the blades, the vortices generated by this outflow do not easily spread to the high-pressure side; as a result, the vortices remain localized, having a minimal impact on cavitation. Conversely, at a negative attack angle, vortices are generated on the working surface of the blade; these vortices tend to spread toward the low-pressure side, having a significant impact on cavitation. It can be seen that at a positive impact angle, the pressure drop coefficient remains relatively constant over a wide range of positive angles, while it increases sharply at negative impact angles ； 3) As the pump flow rate increases, β'1 increases; using a positive injection angle can prevent a negative injection angle from occurring when the pump operates at high flow rates. (6) Blade inlet thickness: The thinner the blade inlet thickness, the more streamlined it is; the further the maximum thickness of the blade is from the inlet, the lower the pressure drop at the blade inlet, and the better the pump’s cavitation resistance. The shape of the blade inlet has a highly sensitive impact on the pressure drop. (7) The balance holes on the impeller: the leakage flow through these holes has a detrimental effect on the main flow entering the impeller. The area of the balance holes should be no less than five times that of the clearance between the seal rings, in order to reduce the leakage velocity and thereby minimize its impact on the main flow, ultimately improving the pump’s cavitation resistance. (8) Surface finish: The smoother the inlet area of the impeller, the lower the hydraulic losses, which significantly improves the pump’s cavitation resistance. (9) Use of cavitation-resistant materials: When it is not possible to completely avoid cavitation due to operational constraints, cavitation-resistant materials can be used to manufacture the impeller, thereby extending its service life. Generally speaking, the smoother the surface of a part, the higher its strength and toughness; the greater its hardness and chemical stability, the better its resistance to cavitation. (10) Using an inducer wheel to improve the cavitation resistance of the pump: Installing an inducer wheel in front of the centrifugal pump impeller can enhance the pump’s cavitation resistance, with very significant effects. Practice has shown that with an inducer added to the centrifugal pump, the pump’s cavitation specific speed can reach around 3000. During the process flow design, the equipment can be appropriately upgraded to prevent cavitation ； 1) Reduce the geometric suction height (or increase the geometric backflow height) ； 2) Reduce suction losses; to this end, efforts can be made to increase the pipe diameter, minimize the length of the pipelines, as well as reduce the use of elbows and other accessories ； 3) When the pump operates at high flow rates, NPSHr increases while NPSHa decreases. Therefore, when determining the installation height, NPSHa should be much greater than NPSHr; otherwise, operation at high flow rates for extended periods should be avoided. 4) Use a double-suction pump at the same speed and flow rate. According to the formula for NPSHr, for two pumps with the same NPSHr, speed, and flow rate, the NPSHr of a pump equipped with a double-suction impeller is 0.63 times that of a pump with a single-suction impeller. 5) When cavitation occurs in the pump, reduce the flow rate or operate at a lower speed.