Temperature and pressure are often measured alongside flow to calculate the energy flow in a pipe, but very often, especially in the water and waste sector, flow rate can be the sole parameter that is measured, either to quantify the flow for fiscal purposes or to control the flow as part of a process.
There is a wide diversity of flow meters and each type has their advantages and disadvantages. Most flow meters are inserted within the flow, often via spool pieces, to ensure the best flow through the meter itself. Sometimes it can be inconvenient to integrate a flow meter within a pipe. Or sometimes a meter provides a temporary replacement or checks on existing equipment. In these cases, the clamp-on flow meter provides a reliable and cost-effective solution.
Clamp-on ultrasonic flow meters operate throughout the world in a variety of applications and installations.
In just one example, a semiconductor manufacturer uses a Baker Hughes portable flow meter to check and verify the performance of installed flow meters in its on-site water-treatment facility. Each department at this manufacturer’s site operates its own discharge line into the water treatment facility. This amounts to over twenty discharge lines, ranging from two inches to 10 inches in diameter in a variety of materials from PVC to stainless steel. In-line flow meters are installed on each discharge line, immediately before the point where the discharge lines enter the waste treatment facility. The volumetric flow rate of each discharge line is monitored on a continuous basis. Based on these measurements, the waste treatment facility bills each department, and this financial penalty motivates each department to produce as little waste as possible.
Naturally, it is vital that the accuracy and functionality of the permanently installed flow meters are verified. The company considered various portable flow meters for this task, but they all proved too bulky, too costly or required an external recording device. However, they eventually tried a Panametrics portable flow meter, and this proved ideal for the job. Parameters for the various discharge pipes are permanently programmed into the meter’s memory, reducing setup times and the flow meter logs flow data on a continuous basis. The data is then uploaded to a PC, plotted, and compared with the data generated by the relevant permanently installed meter. This has shown a correlation with 1% accuracy when compared with a correctly functioning in-line meter.
