DXP Pacific Industrial Pumps

Cortech's Guide to Selecting the Right Metering Pump

Cortech offers metering pumps for a wide variety of applications, including water and wastewater treatment, as well as chemical injection. We represent metering pumps from some of the world’s top pump manufacturers and can help you get the best metering pump for your specific industrial, municipal or commercial application.
What is a Metering Pump?
Metering pumps are specifically designed to convey fluids at very precise flow rates over certain periods of time. Because they move process media with such accuracy, these pumps were coined the term “metering”. While metering pumps tend to be subsets of different pump types, such as positive displacement pumps and centrifugal pumps, the most common type are diaphragm pumps. Diaphragm pumps use a solenoid, mechanical actuation or hydraulic actuation to control the flow rate.
How Does a Metering Pump Work?
Based on what regulating mechanism is used for precise flow rate, metering pumps are often divided into two categories: fixed displacement metering pumps and variable displacement metering pumps.
A fixed displacement metering pump will adjust the flow rate based on the speed of the motor, which ensures that a consistent amount of fluid is conveyed with each rotation. A variable displacement pump, on the other hand, will accomplish consistent flow rates regardless of the motor speed. It is typically based on stroke length or the amount of fluid that is bypassed.
For a metering pump to work, a hollow piston will allow hydraulic fluid to pass through the center port. This pumps the liquid in and out of the diaphragm chamber.
Components of Metering Pumps
There are different types of pumps that can be considered metering pumps, and with each one, the key components may vary. Since diaphragm pumps are the most common, we’ll explore their components below.

  1. Diaphragm
    Diaphragm metering pumps have a diaphragm that provides repeated compression and decompression. This motion changes the volume of the pump chamber. The liquid enters through the inlet check valve during the decompression before it exits through the outlet check valve during compression.
  2. Piston
    A hollow piston is what allows the hydraulic fluid to move through the center port of the pump. Between the piston and the diaphragm, very controlled flow rates are easily achieved with each repeated motion within the pump.

Metering Pump Maintenance
Metering pumps are designed for accuracy, but typically not for conveying large amounts of fluids. Installation and maintenance of metering pumps is generally pretty simple; however, because they have such precise components and motions, it will be important to understand how to make the necessary adjustments to ensure that your metering pump continues to provide the exact flow rate you want for any given application.
Types of Metering Pumps
Metering pumps are essentially variations of other different types of pumps, each made to provide the metering ability and achieve accurate flow rate results.

  • Diaphragm
  • Peristaltic
  • Centrifugal
  • Positive Displacement (Fixed or Variable)

Though diaphragm pumps are most commonly used for metering, you may want to consider a different type of metering pump based on your desired application, process media and other factors.
Applications for Metering Pumps
Metering pumps are specially designed for liquid media that needs to be pumped at specific flow rates. They are most popular when it comes to water and wastewater treatment. They are also great for chemical treatment of water for use in boilers or cooling towers. Metering pumps are also popular in food processing plants when different liquids need to be blended.
Some of the best applications for metering pumps include:

  • Water and Wastewater Treatment
  • Chemical Treatment
  • Food Processing
  • Oil and Gas
  • Agricultural
  • Viscous Materials

Which Manufacturers Make Metering Pumps?
Cortech Engineering offers high-quality metering pumps from the world’s leading manufacturers. We can match you up with the right brand and the ideal pump for your application. Cortech represents metering pumps from the following top brands:

  • Milton Roy
  • Verder
  • Liquiflo
  • LMI

How to Select Metering Pumps
There are various factors you’ll want to keep in mind when selecting a metering pump. First is the process media: Is it water, is it a slurry or is it a highly viscous fluid such as oil? Second, you’ll need to consider the amount of media that needs to be processed. Lastly, you’ll have to know what your desired flow rate is. Metering pumps are so precise, so you’ll want one that can handle the materials you need to pump, the total volume you need to pump and the metered volume you need to pump based on specific time periods.
Cortech will help you figure out your metering pump needs and select the ideal metering pump for your specific applications. We’ll show you the best that manufacturers like SEEPEX, Milton Roy, Liquiflo, LMI and Verder have to offer.
Contact Cortech Engineering today to learn more about metering pumps and how to purchase the ideal metering pump for your application.