Damage analysis of water supply and drainage pipelines

In the process of pipeline installation and operation, although anti-corrosion technology has been valued and applied, pipeline corrosion is still inevitable due to factors such as non-standard operations during the construction process or the harsh environmental conditions in which the pipeline operates year-round. For large-scale damage such as uniform corrosion of pipelines, replacement of pipelines can generally be used to deal with it; For local corrosion of pipelines, due to the small damage area and high cost of replacing pipelines, repair techniques are often used for reinforcement treatment in production.

Common pipeline reinforcement technologies include welding reinforcement, fixture reinforcement, composite material reinforcement, etc. Among them, composite material reinforcement technology has been increasingly applied due to its high efficiency and reliability; As a typical composite material, carbon fiber composite material has greater advantages in the reinforcement application of small area damage in pipelines compared to welding reinforcement or fixture reinforcement.

Characteristics of carbon fiber composite materials

Using carbon fiber resin based composite materials as reinforcement materials for water supply and drainage pipelines can not only restore the pressure bearing capacity of the pipeline, but also avoid problems such as stress and strain at defects in the pipeline, greatly improving the reliability of pipeline repair and reinforcement. Therefore, the application of carbon fiber resin based composite materials has significant technical advantages in pipeline defect repair and reinforcement.

Principles of Strengthening Carbon Fiber Composite Pipeline

During the operation of the water supply and drainage pipeline, the force around the reinforcement part of the pipeline mainly comes from the pipeline pressure near the defect. The pressure here will cause the pipeline to expand, and the strain caused by the expansion will act on the filling agent at the defect location. The filling agent will transfer the force at that location to the carbon fiber composite material in the reinforcement layer, which has good mechanical properties and can greatly supplement the strength of the filling agent. Coordinate the strain at the entire repair layer with the overall strain of the pipeline to avoid stress concentration. At the same time, it also avoids the problem of separation between the repair layer and the water supply and drainage pipeline due to inconsistent strain. After the repair is completed, the reliability of the defective pipeline is significantly enhanced, which can effectively ensure the safe operation of the water supply and drainage pipeline.

Technical Route for Strengthening Carbon Fiber Composite Pipeline

In the engineering practice of applying carbon fiber composite materials to the repair and reinforcement of water supply and drainage pipelines, the position of the water supply and drainage pipeline with pressure leakage should be located first, the water supply and drainage pipeline should be exposed, and the damage situation of the water supply and drainage pipeline should be further confirmed. Large area damaged and irreparable water supply and drainage pipelines should be replaced, and repair measures should be taken for small area damaged water supply and drainage pipelines. Before repairing the pipeline, it is necessary to perform surface treatment on the defect area of the pipeline. First, remove the rust at the defect area through mechanical treatment, and then use alcohol or acetone to remove foreign objects at the defect area. After the surface treatment is completed, use the prepared filling agent to fill and level the defective parts of the pipeline, and apply adhesive to the surface of the pipeline to increase the adhesion between the carbon fiber composite material and the water supply and drainage pipeline. Finally, carbon fiber composite material is tightly wrapped on the surface of the pipeline, and heating and related curing treatment are carried out to complete the defect reinforcement treatment of the water supply and drainage pipeline.

In practical applications, the number of coils wrapped with carbon fiber composite materials for water supply and drainage pipelines needs to comprehensively consider various factors, including the tensile strength and yield strength of the pipeline material, pipeline wall thickness and remaining pipeline wall thickness, as well as the tensile modulus and maximum plastic elongation of carbon fiber composite materials.

After completing the winding and reinforcement treatment of carbon fiber composite materials, cathodic protection and waterproofing treatment should be carried out on the surface according to the technical requirements for anti-corrosion treatment of water supply and drainage pipelines, further enhancing the reliability of the repaired water supply and drainage pipelines. Then, pressure testing will be conducted. After the pipeline pressure test is normal and there are no obvious defects, the water supply and drainage pipeline will be buried to complete the defect reinforcement treatment of the water supply and drainage pipeline.