The Hydraulic Institute (HI) published a new “American National Standard for Effects of Liquid Viscosity on Rotodynamic (Centrifugal and Vertical) Pump Performance (ANSI/HI 9.6.7)” in January. The standard replaces the more than 40-year-old HI viscosity correction nomographs, and is designed to predict the performance change of rotodynamic pumps operated on viscous liquids exhibiting Newtonian behavior relative to their performance on water, which is the basis for most published curves.
HI said that eliminating the need for interpolating graphic solutions is a development of major technical significance and practical application. The standard will provide valuable guidance to pump manufacturers, users, and others who have an interest in the performance of rotodynamic pumps, according to HI.
HI members developed the new standard in collaboration with representatives from France, Germany, Italy, Japan, and Switzerland. The standard includes contributions from an array of prominent industry experts and veterans, said HI.
A variety of rotodynamic pumps of conventional design are covered, including open or closed impellers, and single or double suction pumps. The standard also includes information on methodology, definitions of symbols and terms, flowcharts which outline the procedure, theoretical explanations behind the methodology, and a method for estimating net positive suction head required. ✦
