Monitoring of Corrosion in the Pipeline of a Distribution Network Using Weight Loss Method and Image Processing Technique

This study investigates the monitoring of corrosion in the distribution network pipeline in Patna (Bihar), India, using a weight loss method and an image processing technique. The seven coupons were injected into the pipeline of the distribution network and ejected after 45, 90, 135, 180, 225, 270, and 315 days. The corrosion rate was calculated by weighing the initial and final weight of coupons. It was found to be 0.035, 0.078, 0.048. 0.035, 0.028, 0.052, and 0.039 mm/year during 45, 90, 135, 180, 225, 270, and 315 days, respectively. Scaling rate found at 45, 90, 135, 180, 225, 270, and 315 days was 0.006, 0.037, 0.042, 0.049, 0.011, 0.018, and 0.033 mm/year, respectively. Surface analysis was performed using the scanner method and MATLAB software. Coupons were first scanned using a scanner adjusted to 4800 ppi. A scanned image was imported into MATLAB. An algorithm was used based on color analysis. The output of a text file was generated that gave the corrosion pit in terms of pixels. The MATLAB analysis shows that the surface corrosion area sum of both sides of the coupon was 6.24, 6.39, 6.49, and 6.48 cm² in 45, 90, 135, and 180 days, respectively. This study concludes that scale formation on the pipe surface decreased the corrosion rate. Corrosion and scaling were found in the opposite trend. SEM analysis shows that pitting corrosion was increasing with increasing duration of time. Physicochemical analysis shows that the water was alkaline. The presence of a greater concentration of hardness, alkalinity, and less concentration of chloride, sulfate, and DO water was found to have a scaling tendency. XRD analysis of iron dust represents the presence of salts in water, which is responsible for the scaling behavior of water.