Blog

3 Reasons To Choose Positive Displacement Pumps

It can be very difficult to choose between a positive displacement pumps and a centrifugal one. The differences between these pumps are often not that clear. In this article, we take a closer look at the way these pumps operate, the unique positive displacement pump characteristics and when to use them– making the choice ever so much easier.

How does a positive displacement pump work?

A positive displacement pump moves a trapped liquid from the inlet to the discharge pipe. By creating flow, this produces pressure. Because they can transfer highly viscous fluids at high pressure and low flow rates, the efficiency of PD pumps are not compromised or affected by this pressure.

They’re superior to centrifugal pumps because they can run at any point on their curve (handling difficult conditions where centrifugal water pumps could fail). In addition, by operating at lower speeds than centrifugal pumps, these pumps have less shear, allowing gentle operation for shear-sensitive fluids.

Why choose positive displacement pumps?


1. Efficiency at increased viscosity

Centrifugal pumps struggle to pump viscous liquids. With positive displacement pumps, their efficiency increases with increasing viscosity. Simply put, the thicker the liquid, the less slip there is in the pump (higher viscosity requires more energy to move). The performance of the positive displacement pump actually improves under these conditions, because the liquid doesn’t easily slip through the gaps and clearances near the rotors.

2. Low flow requirements

When lower flow is required, a centrifugal pump can run off its BEP, which increases energy usage, negatively impacts performance, and may even damage the pump.

With a positive displacement pump, you can change the speed to regulate flow. This means you can provide a constant flow of fluid at a given speed. This makes the positive displacement chemical pump the better choice for pressure and flow when operating a pump off its BEP.

3. Metering applications

These pumps are often used for metering because of their ability to offer constant flow. PD pumps are thus well suited for metering applications where precise quantities of fluids and measured flow is needed for specific process requirements. The types of pumps used for metering include bellows, gear, peristaltic, diaphragm, and piston.

Positive displacement pumps are better than centrifugal pumps for some applications, but it’s not always a clear choice. If you’re unsure, give us a call on 1-800-367-4180 (toll-free). We are your chemical pumps supplier in Canada and we’re here to help you choose, install, maintain, and monitor a variety of equipment. And to answer questions about things you’ve previously tried gone wrong.

Recent Posts

  • Blog

No More 2 A.M. Call-Outs: Make Your Pump System Reliable

We know middle-of-the-night alarms are not a badge of honour. They’re a sign your pump…

1 week ago
  • Blog

Quiet the Shake – Smoothing Out Lines with Pulsation Control

If your chemical lines chatter, gauges flutter, or injection points “spit”, you are seeing normal…

1 week ago
  • Blog

The Hidden Money Leak in Your Pump Room

Your pumps may be moving water just fine. But they could be quietly draining your…

1 week ago
  • Blog

Why is Our Water Pressure All Over the Place?

You turn a valve, and pressure spikes. Then it sags. Then it’s fine… until shift…

1 week ago
  • Uncategorized

Evaluating the Common Concerns About Mag Drive Pumps

Mag-drive centrifugal pumps are widely used in industries where leak-free and low-maintenance operation is critical.…

2 weeks ago
  • Blog

Understanding the Importance of Oiling in Industrial Pumps

Industrial pumps play a vital role across diverse industries, powering processes by moving liquids efficiently…

2 weeks ago