Apply it for:

The 2018 revision of HI 9.8 formally introduced guidance on using Digital Twins for intake design validation. Instead of a one-time physical model, owners now build a real-time CFD model connected to SCADA.

This allows:

For designers, the move is toward generative design—using AI to optimize wet well geometry against HI 9.8 constraints automatically.

Here’s a useful, structured content piece on ANSI/HI 9.8 – Rotodynamic Pumps for Pump Intake Design, aimed at engineers, plant operators, and design professionals.

A single pump is easy. When you put two or more pumps side-by-side, the hydraulics interact. HI 9.8 mandates:

The standard (9.8-2018, the latest revision) applies specifically to rotodynamic pumps operating in wet well or open sump configurations. It focuses on:

It does not cover positive displacement pumps or closed-loop systems with pressurized suction headers (though those principles often cross-apply).

Adopt ANSI/HI 9.8 as the mandatory design basis for all new rotodynamic pump intake structures where reliability is critical (water/wastewater, power plants, industrial cooling, flood control). For standard, small, low-cost pumps (e.g., irrigation), a simplified subset of rules may suffice. For large, critical, or space-limited projects, budget for physical or CFD model testing per HI 9.8 guidelines.

Score (1–10): 9.2/10 – Indispensable, but conservatism and learning curve prevent a perfect score.

Standard NPSHa calculations assume steady, uniform flow. However, vortices and swirl reduce NPSHa dynamically.

HI 9.8 introduces the concept of Vortex-Induced NPSH Penalty. If a Type 3 vortex (see Part 4) is present, the effective NPSHa can drop by 20–30% due to localized pressure depression.

The standard’s requirement:

NPSHa must exceed NPSHr by the margin specified in HI 9.6.1 plus an additional 1.5 ft (0.45 m) for every vortex type above Type 2.

In practice, most engineers using HI 9.8 design for NPSHa ≥ 1.2 x NPSHr, with a minimum absolute margin of 3 ft (0.9 m).