Smart Magnetic Flowmeters Reduce Downtime, Operation Costs

The South Florida Management District (SFWMD) is the oldest and largest of Florida’s five water management districts, covering 16 counties from Orlando to the Florida Keys, where 3 billion gal of water are used every day. The SFWMD serves a population of 7.7 million residents and employs 1,800 people. Golden Gate Water Treatment Plant is one of the plant sites under SFWMD, providing treatment of up to 2.1 million gal of water per day of out of eight wells.

Project Background

In order to measure the water withdrawal required by the SFWMD, Severn Trent Environmental Services utilized propeller-style flowmeters. However, these flowmeters were prone to bacterial growth and worn-out parts, leading to inaccuracy, unplanned shutdowns during peak usage times and high maintenance costs. Because the propeller-type meters were used for reporting water usage, they were required to be recalibrated every year at a cost of $1,100 per meter. This required Severn Trent to keep spare meters in inventory and schedule annual shutdowns for each of the wells. To address these issues, Severn Trent replaced these critical reporting meters with Emerson magmeters with the Integral Meter Verification diagnostic. Thoughtful selection of the magmeter materials solved the issue of bacterial growth, while the integral meter verification diagnostic met the annual verification requirement.

System Benefits

Utilizing Emerson magmeters with the integral diagnostic, Severn Trent Environmental Services can monitor the health of the magmeter system and record the health of the magmeter. They can then generate reports that capture the real time measured values of all critical components in the magmeter system. The measurements of the critical components are stored in the transmitter and are available for report generation through the local operator interface, a handheld HART communicator or Emerson’s AMS asset management software. Users have the ability to select the accuracy criteria for each of the critical components including the wiring between the sensor and the transmitter, the electrode resistance and the coil resistance and inductance. If any of these components falls out of the user-specified accuracy, an alert is generated.

Full-Scale Operation

Severn Trent Environmental Services realized a first year savings of $10,000 in calibration costs alone. It also has eliminated its spare parts inventory and redeployed onsite maintenance staff to other locations. The Emerson magmeters have performed flawlessly since installation. Yearly verification results indicate the meters are still well within their stated accuracies. This has resulted in a more profitable and efficient water service operation for the SFWMD.

Tom Johnson is marketing manager for Rosemount Flow. For more information, please contact Robert Migdal, instrumentation and controls manager, Severn Trent Services, at 239.694.3310.