Categories: Uncategorized

Pump Basics: Affinity Laws

Law 1- Speed is directly proportional to Flow.

Law 1 means that as RPM is reduced, flow (GPM) is reduced in a linear relationship. For example, if RPM drops to 70% of the original, GPM drops to 70% of the original.

Law 2 – Head is proportional to Flow squared.

Law 2 means that as RPM is reduced, pressure (feet of head) is reduced by the square. For example, if RPM drops to 70% of the original, feet of head would drop by (70% x 70%) = 0.72 = 0.49 or 49% of the original.

Law 2 – Input power is proportional to Flow cubed.

Law 3 means that as RPM is reduced, power consumption (brake horsepower) is reduced by the cube. In the same example the power would drop to (0.7 x 0.7 x 0.7) = (0.7)3 = 0.343 or 34.3% of the original.

Recent Posts

  • Blog

Data-Driven Maintenance – Why Pumps and Mixers are your Best Bet for Predictive Analytics

Data-Driven Maintenance - Why Pumps and Mixers are your Best Bet for Predictive Analytics When…

2 weeks ago
  • Blog

How Inline Static Mixers Are Transforming Chemical Dosing Accuracy

Precise chemical dosing is critical in water treatment, industrial manufacturing, and chemical processing. However, achieving…

2 weeks ago
  • Blog

When and Why Commercial Facilities Need a Pressure Booster Pump

Low water pressure in commercial buildings isn't just a nuisance—it can disrupt essential operations. In…

2 weeks ago
  • Blog

What Makes Grundfos Pumps a Top Choice for Canadian Process Industries?

Meeting fluid handling requirements in Canadian process industries isn’t just about durability. It’s about efficiency,…

2 weeks ago
  • Blog

Circular Economy for Plant Managers

Most manufacturers still operate with a "take-make-dispose" mindset: extract resources, process them once, and then…

2 weeks ago
  • Blog

People Power is the Key to Reliability in the Age of Smart Equipment

Even with pumps that can diagnose themselves and mixers that auto-adjust, the biggest factor in…

1 month ago