Home - News - Industry News - Standards for Maintenance and Inspection of Anti-Corrosion Layers on Seamless Steel Pipes
February 02, 2026
Seamless steel pipes are often used for oil, gas, and water supply and drainage. The anti-corrosion layer is like its "protective coat", which can resist corrosion and aging, and directly determines how long the steel pipe can be used and whether it can operate safely. Here are simple standards for the maintenance, inspection, and repair of seamless steel pipes, regardless of whether they are buried, overhead, or outdoors. The main focus is to effectively manage daily tasks, conduct regular inspections, and promptly repair any damage.
In daily use, the main task is to protect the anti-corrosion layer from damage and clean up debris around it. Do not let sharp objects scratch or heavy loads press the seamless steel pipe. Do not randomly dig or pile heavy objects around buried steel pipes. Add anti-corrosion pads at the contact points between overhead steel pipes and supports to prevent friction damage. Regularly clean up oil stains, water accumulation, and dust on the surface of steel pipes. For buried pipes, check for any leakage of corrosive substances in the surrounding area and inspect the soil for abnormalities. For overhead pipes, ensure that the supports are secure to prevent movement that could damage the anti-corrosion layer. Additionally, never weld or drill holes in the anti-corrosion layer. If necessary, promptly repair any damage after the operation.
The inspection cycle depends on the environment. In a normal environment, buried steel pipes should be inspected once every 1-2 years, and overhead or indoor ones once every 2-3 years; in highly corrosive environments such as coastal areas and chemical zones, all steel pipes should be inspected once every 6-12 months; for steel pipes used for high-pressure oil and gas transmission, partial inspections should be carried out every quarter and comprehensive inspections once a year.
The inspection mainly focuses on the following points: first, check the appearance for holes, cracks, bulges and peeling; second, check the adhesion, which is qualified if there is no peeling or delamination when tested by special methods; third, measure the thickness to ensure it is not lower than the design standard; fourth, electric spark leak detection, which is a must for buried seamless steel pipes. If there is no electric spark or breakdown, it is normal. After inspection, if there are no defects, the item can be used normally. Minor damage should be repaired promptly, while extensive damage requires a shutdown for rectification.
When damage is detected, it must be repaired within 24 hours. The repair material should be compatible with the original anti-corrosion layer, and the repaired area should be inspected again to ensure it meets quality standards before use.
Minor Damage (less than 10mm): Remove any rust and impurities, grind the area down to the metal, and then apply repair paint or paste. Ensure that the application area extends at least 50mm beyond the damaged section.
Moderate Damage (10-100cm²): Remove the damaged section completely and thoroughly eliminate any rust. Repair the damaged area layer by layer, following the structure of the original anti-corrosion layer.
Large Area Damage (more than 100cm²): Completely remove the original anti-corrosion layer, re-derust the surface, and perform anti-corrosion treatment. If rust pits are present on the pipe, conduct repair welding before applying the anti-corrosion layer.
For damage occurring at joints and elbows, it is important to thicken the anti-corrosion layer and add a protective sleeve to enhance the durability of the anti-corrosion effect on the seamless steel pipe.
Records should be maintained, and files should be established for each maintenance, inspection, and repair activity to ensure traceability. For pipe sections that are frequently damaged, it is important to investigate the underlying causes, enhance protection measures, and reduce the inspection frequency. Maintenance and inspection personnel must undergo professional training and become familiar with operational procedures before starting their duties. They should also strictly adhere to standards to ensure the anti-corrosion layer remains effective.
