Abstract — Inspect, assess and repair forms the integrity-management cycle. Repair-and-reinforcement is a critical lever for both integrity and service-life extension. This article summarises and categorises available methods and compares their merits.
Three Families, Seven Sub-Techniques
- Welding — weld overlay, weld patch, sleeve
- Mechanical clamps — clamp, clamp with epoxy injection
- Fiber composite — glass-fiber composite, carbon-fiber composite
On combined performance and outlook, carbon-fiber composite reinforcement leads.
Introduction
In-service pipelines accumulate defects from corrosion, fatigue and mechanical damage, lowering the maximum safe operating pressure and reliability. China operates more than 40 000 km of pipelines; maintaining integrity and safe operation is a major industry challenge.
The inspect–assess–repair cycle is the effective workflow:
- Inspect — internal or external inspection detects coating and wall defects
- Assess — elasto-plastic, fracture and damage mechanics models estimate the residual strength of defective pipe and predict remaining life
- Repair — apply suitable methods to restore safe operating pressure
This article focuses on classifying and comparing repair techniques as a reference for plant managers and field engineers.