Most pump curves are developed with pure water, however, pumping a fluid more viscous than water will result in a reduction for pump performance - even if the fluid reference density is the same as water. AFT Impulse employs the methods described in ANSI/HI 9.6.7-2021ANSI/HI Standard 9.6.7-2021, Rotodynamic Pumps - Guideline for Effects of Liquid Viscosity on Performance, 2021, published by Hydraulic Institute, 300 Interpace Parkway, Building A, 3rd Floor, Parsippany, New Jersey, USA to correct for losses in performance due to viscosity.

Correction factors referred to as CH, CQ and CE are defined. These correction factors are defined as:

Scope of Correction

It is important to keep in mind that, like all mathematical models, this standard is not universally applicable. Below are the primary requirements:

• Single or multistage centrifugal pump

• Essentially radial discharge with specific speed under 3000 (US units)

• Newtonian Fluid

• Kinematic viscosity between 1 and 4000 cSt

For detailed information regarding these limitations and the application of the standard, please consult ANSI/HI 9.6.7-2021