Over a century, waste treatment plants have measured wastewater and sewage using Venturi Flow Meters with differential pressure indicators. Why? Because Venturi Flow Meters offers lifespan reliability that is unmatched by any other metering technology on the market.
In recent years Magnetic Flow Meters have replaced existing venturi in plants and specifications. The reason is that they offer a lower entry cost and claim to be maintenance-free. While this may be true, it doesn’t tell the whole story.
There is no dispute that the purchase price of a Mag Meter is lower than that of a Venturi. Now consider that many of the wastewater treatment plants built in the United States opened in the mid-50s. Those plants have been in operation for over 70 years, where many cast iron venturi meters, which were installed back then, are in working condition even as of today.
The second claim of maintenance-free operation areMag Meter, which are essentially an electronic device. Like your PC, Mag Meters don’t need much maintenance and maybe occasional calibration check. The downside is, like your PC, they only have a lifespan of 5 to 10 years and then they have replaced. Venturi Meters are physical devices, with no moving parts that create a pressure difference, which is measured by a Differential Pressure Transmitter. The transmitter is an electronic device with lower cost and easy replacement, unlike breaking into the mainline to replace a Mag Meter.
There is no doubt that Magnetic Flow Meters have come a long way and offer reliable flow measurement. Even with such excellent reliability, they still cannot be compared to the robustness of a venturi with a differential pressure transmitter. For more information on specifying the correct flow meter for your wastewater applications, contact Tek-Trol’s Support.
