Sizing And Selecting The Proper Metering Pump

In process application, large amounts of chemicals are used during daily operations and the volumes of chemicals are large and very precise, with exact amounts delivered according to strict injection schedules. Thus the pressures - from very high to very low – for injecting the chemicals should be governed precisely. Metering pumps have—whether mechanically, hydraulically or electronically actuated—raised to the fore as a technology of first choice for the injection of chemicals in processing and agricultural applications, but within the realm of metering pumps there are many different styles and modes of operation. The article explains the different metering-pump technologies and illustrates how the user should select the proper size and style depending on the injection application for which the pump will be tasked.

A typical process application can consume large amounts of chemicals during daily operations. While the volumes may be large, though, they must also be very precise, with exact amounts delivered according to strict injection schedules. The pressures—from very high to very low—that the chemicals are injected at must also be governed precisely. This demand for precise flow rates at predetermined schedules and pressures requires the use of a very specific pumping technology, one that can ensure successful, reliable adherence to the injection schedule and fluid volumes.

Metering pumps have—whether mechanically, hydraulically or electronically actuated—risen to the fore as a technology of first choice for the injection of chemicals in processing and agricultural applications. Today’s metering-pump technology can be easily set to deliver exact volumes according to a set schedule, and at varying pressures.

But within the realm of metering pumps there are many different styles and modes of operation.

Know the Variables

When determining which metering pump is the best option for a chemical injection application there are a number of variables that must be taken into consideration, including:

• Flow Rate: Metering pumps should never be oversized, meaning that determining the exact flow rate that is required for the application is of paramount importance. With that in mind, a metering pump should be sized so that the maximum expected flow rate is 85 to 90 per cent of the pump’s capacity, which will leave room for additional capacity, if needed.