The Hydraulic Institute (HI,, an association of pump technology providers, published a new American National Standard for Rotodynamic (Vertical) Pumps for Nomenclature and Definitions (ANSI/HI 2.1-2.2-2008). The standard applies to vertically suspended pumps, including single-casing (open pit intake) submersible pumps and discharge through column types (diffuser, volute, and axial flow). Also included are double casing (can or suction barrel intake – diffuser and volute) and in-line casing diffuser pumps.

These pumps are typically driven by vertical electric motors or horizontal engines with right-angle gears. The standard also includes types, nomenclature, and definitions for these pumps.

Excluded from the scope of this document are:
A. Vertical in-line pumps
B. Horizontal centrifugal pumps mounted vertically such as sewage pumps
C. Vertical, overhung impeller, close coupled, and submersible single stage submersible pumps

The standard, designated by HI product code A105, is available in hard copy or secure PDF format from the Hydraulic Institute for $85.00. For more information, or to order, visit the HI e-Store.