WorldWide Drilling Resource®

Four Keys for Selecting an Irrigation Flow Meter Part 1 Adapted from Information by Katie Englin Agricultural Irrigation Specialist, Seametrics Companies and agencies in the U.S. and abroad continue to require water flow meters for new and existing agricultural irrigation applications to measure and manage surface and groundwater use. There is a growing need to conserve resources plus balance the water needs of agriculture with other industries; and with the growing population, residential use is driving water conservation as never before. Tips to help with proper flow meter selection: 1. What is the application? Understanding the fluid media, flow range, temperature, pressure, line size, needed signal outputs, and available space for installation are all necessary to ensure proper flow meter selection. Let’s review each piece: \ Media is groundwater, surface water, water from a pond, or a lagoon of manure slurries. While a mechanical meter may work fine for a clean water application where the flow range falls within the meter’s capabilities, magnetic flow meters offer the highest accuracy and performance in both clean and dirty water applications. With no moving parts, weeds, trash, and slurries which may otherwise become entangled in a mechanical meter, easily flow through magnetic meters. \ Knowing the minimum and maximum flow range is most critical when selecting a mechanical propeller flow meter. They require a minimum amount of flow to turn the bearing assembly and propeller fast enough to ensure an accurate reading. If the flow rate exceeds the rating of the mechanical meter, the bearing assembly can suffer costly damage, and the meter will not function properly. With no moving parts to wear out, magnetic flow meters offer higher accuracy over a broader flow range than mechanical meters. \ The majority of flow meters offered for this market are rated up to 150 psi (pounds per square inch) and 140ºF (60ºC) operating temperature. Most of these applications fall well within this temperature and pressure range, but it’s always wise to confirm the application temperature and pressure. \ Knowing the line size will help determine the style of meter. Both electromagnetic and mechanical meters are available in full-bore and insertion style configurations. For cost and ease of installation, an insertion style may be the best option for larger line sizes. Next month, we’ll discuss signal output, available space, accuracy, and maintenance. WTR 25 WorldWide Drilling Resource ® JUNE 2020