Pipeline in the course of service, will inevitably be due to corrosion, fatigue and mechanical damage caused by pipeline defects, reducing the maximum safe operation of the pipeline pressure and reliability. Practice has proved that the inspection of the pipeline - assessment - repair and reinforcement is to ensure the integrity of the pipeline an effective way. Using the internal detection or external detection technology, the defects and damage of the coating and the pipe body are evaluated, and the elasto-plastic mechanics, fracture mechanics and damage mechanics model are evaluated to evaluate the residual strength of the defect pipeline, and the deformation dynamics Residual life of defective pipelines.

Pipeline repair and reinforcement technology is to ensure the integrity of the pipeline and extend the useful life of the pipeline an important means. For the pipeline repair technology research and development is also an effective way to save social resources, pipeline maintenance and reinforcement methods can be summed up into three types and eight small types:

(1) welding type: (a) surfacing; (b) patch; (c)

(2) fixture type: (d) ordinary fixture; (e) fixture injection epoxy;

(3) fiber composite material type: (f) glass fiber composite material repair; (g) carbon fiber composite material repair; aramid fiber composite material repair.