FOR 10 YEARS, 56 vertical utility pumps operated continuously and without incident at one of the world’s largest chemical companies, located in Germany. After almost 100,000 operating hours in that span, it was necessary to conduct thorough, detailed asset maintenance. Two of the vertical pumps would have their primary flanges surveyed for flatness. The flanges are the primary attachment point between the concrete foundation of the building and the vertical utility pumps.
Due to the enormous size of the pumps, it’s particularly important that the flange connection is flat and leveled to ensure the correct fit. A small unevenness at the flange seat can cause the pump suction nozzle to sit improperly, sabotaging efficiency. Such an imperfect junction can also result in energy losses, as well as increased pump stress. The strains can result in additional costs and unplanned downtime.
LASER-MEASUREMENT TECHNOLOGY
With the help of the LevAlign Expert system from Prüftechnik, a division of Fluke Reliability and the Fluke Corp., Everett, WA, (fluke.com), the flanges were measured when the pumps were dismantled. Once the flanges were exposed, they were found to be contaminated and partially corroded from years of continuous use. Conducting the measurement required careful cleaning and a slight sanding of the flanges.
The first step in the measurement process was to measure the flange diameters. Once this information was collected, the LevAlign Expert software was able to conduct the flatness measurement. For the measurement, the flange was divided into two concentric circles of 16 equal sections, providing 32 measuring points for each flange. Sixteen were on the inner circle and 16 on the outer loop, all at an angular distance of 22.5 deg. to each other. Once these points could be added to the software, the instrument was placed in a stable position. It created a level plane by spinning a laser at high speeds.
Technicians wore safety harnesses to collect the measurement data as the measurement locations were on the edge of the 2-m flange, which opened to a 5-m drop. With the sensor carefully positioned at each of the 32 points, measurement points were collected.
RESULTS AND BENEFITS
The measurement data revealed an unexpectedly good result on both flanges. The flatness of the flange seats was within tolerance. This meant that it was not necessary to flat-grind the flanges. The observed deviations in flatness were so small that they didn’t have a significant influence on the correct fit or the operating behavior of the pumps.
All flange seats are now successively measured using the LevAlign Expert system to document the actual state of the utility pumps. The process is possible because the system provides the measurements relatively quickly.
For more information, visit flukereliability.com.
