Newtonian vs. Non-Newtonian Fluids: Why It Matters for Your Pump Selection

When selecting pumps, valves, and fluid handling equipment, understanding your fluid's behavior is critical. One key distinction? Newtonian vs. Non-Newtonian fluids.

At Professional Pump, we know the challenges different fluid types bring to industries like Sanitary, Industrial, Water & Wastewater, and Pulp & Paper. The right pump can make all the difference, and we’re here to ensure you get the best fit for your application.

Newtonian vs. Non-Newtonian Fluids: What’s the Difference?

Newtonian Fluids

Newtonian fluids maintain a constant viscosity regardless of applied shear stress—meaning their flow behavior is predictable. Examples include:

• Water
• Mineral oil
• Gasoline
• Alcohol

Non-Newtonian Fluids

Non-Newtonian fluids change viscosity when subjected to shear stress. Their flow can be unpredictable and requires careful pump selection. Examples include:

• Dilatant Fluids (Shear Thickening) – Viscosity increases under stress.
  • Quicksand
  • Cornstarch and water
  • Silly putty
• Pseudoplastic Fluids (Shear Thinning) – Viscosity decreases as shear increases.
  • Ketchup
  • Paint

This chart shows how viscosity changes with respect to the amount of shear/stress applied to the fluid.

• Rheopectic Fluids – Like dilatant fluids but time-dependent.
  • Gypsum paste
  • Cream
• Thixotropic Fluids – Viscosity decreases over time under stress.
  • Glue
  • Asphalt
  • Cosmetics
  • Paint

This chart shows how viscosity changes in respect to shear applied over time to the fluid.

Why This Matters for Your Pump

Viscosity impacts pump performance and efficiency. Newtonian fluids have a straightforward flow-to-pressure relationship, while Non-Newtonian fluids require pumps designed to handle shear-thinning or shear-thickening properties.

Got a tricky fluid handling challenge? We’ve got the expertise to match the right pump to your needs. Contact Professional Pump today, and let’s find the perfect solution for your operation!