The primary objective of ANSI/HI 9.8 is to guide the design of an intake structure so that the approaching flow mimics an ideal fluid environment. Rotodynamic pumps—whether vertical turbine, horizontal split-case, or end-suction—are highly sensitive to the geometry of their approach channels.
Used in natural bodies of water like lakes, rivers, or oceans, unconfined intakes require specific submergence depths to counteract the unpredictable nature of cross-currents and waves. Acceptable Hydraulic Criteria ansi hi 9.8 rotodynamic pumps for pump intake design
Standard NPSHa calculations assume steady, uniform flow. However, vortices and swirl reduce NPSHa dynamically. The primary objective of ANSI/HI 9