How to detect the wall thickness reduction of magnesium air duct during daily maintenance?
Publish Time: 2025-01-09
Visual inspection: During routine inspections, maintenance personnel can first conduct visual observations. Carefully inspect the outer surface of the magnesium air duct to see if there are corrosion spots, pits, or signs of wear. Although this cannot accurately measure the wall thickness, some obvious local corrosion areas often mean that the wall thickness may have been reduced. For example, if rust seeps out or the color changes abnormally on the surface of the duct, you need to focus on this area, which may be an external manifestation of thinning wall thickness.Caliper measurement: For suspected problematic areas, a simple and easy-to-use caliper is a preliminary measurement tool. Place the measuring claws of the caliper precisely on both sides of the outer wall of the duct, measure its outer diameter, and then calculate the difference in the known initial outer diameter of the duct to roughly estimate the degree of wall thickness thinning. However, this method has limited accuracy and can only be used for small, relatively flat measurement points, and it is difficult to cover the entire duct surface.Ultrasonic thickness gauge detection: This is a more professional method. The ultrasonic thickness gauge uses the propagation characteristics of ultrasonic waves in different media to emit ultrasonic pulses to the duct wall and accurately calculate the wall thickness based on the time difference of the reflected wave. During operation, you need to first apply coupling agent on the surface of the duct to ensure that the probe is in good contact with the pipe wall, then slowly move the probe along the pipe section, measure point by point, generate detailed data of the pipe wall thickness, and accurately locate the area of wall thickness thinning.Radiographic detection technology: Radiographic detection can be used when the accuracy requirements are extremely high and the environment of the magnesium air duct is sensitive. It emits X-rays or γ-rays to the duct, and images are formed according to the attenuation degree of the rays after penetrating the pipe wall to reflect the wall thickness. However, this method is costly and complicated to operate, and the rays have radiation risks. It requires professional protection and operation, and is often used in key parts or troubleshooting stages.Regular sampling and disassembly inspection: For magnesium air ducts in large ventilation systems, representative pipe sections can be regularly selected for disassembly. After cutting the magnesium air duct section, use precision measuring tools to measure the wall thickness in all directions, which can not only accurately know the wall thickness thinning data, but also visually observe the internal corrosion condition. However, this method is a destructive test and cannot be performed frequently. The sampling cycle must be reasonably planned.Monitoring operating parameters to assist judgment: Daily record the operating parameters such as wind speed, wind pressure, and air volume in the air duct. If the ventilation efficiency is found to be gradually reduced, after excluding other equipment problems such as the fan, it is likely that the thinning of the duct wall thickness has led to changes in the pipe diameter and increased wind resistance, which can indirectly infer the wall thickness and provide direction for further accurate detection.Establish maintenance file comparison and analysis: After each test, the data is recorded in detail in the maintenance file, including the measurement location, time, wall thickness value, etc. Through long-term accumulation and comparison, the trend of thinning wall thickness can be clearly seen, possible risks can be predicted in advance, and maintenance and replacement plans can be reasonably arranged.
