It is an effective repairing method to reinforce steel pressure pipes by circular bonding of carbon fiber fabric. Especially for pipelines with defects, the circular stress of internal pressure pipes can be effectively reduced.

Round steel pressure pipeline is mainly aimed at oil and gas transmission pipeline. Because of corrosion and mechanical wear, local defects such as grooves, thinning and holes are often damaged. These damages will lead to the decrease of reliability and durability of pipeline.

How to repair damaged pipelines is a problem faced by oil and gas transportation departments. To this end, pipeline reinforcement has become an indispensable and regular work in the contemporary era. Aiming at the research of repairing and strengthening technology for damaged pipelines, many methods have been developed, which can be roughly summed up as welding type, casing, pipe change, fixture type, etc.

The construction technology of these methods is relatively complex, so there are some limitations in engineering application. Carbon Fiber Reinforced Polymer (CFRP) is the most promising repair and reinforcement technology because of its light weight, high strength, high temperature resistance, corrosion resistance, thin thickness, no increase in structural size and simple operation.

CFRP is used to reinforce damaged pressure pipelines. Because different longitudinal reinforcement ranges of CFRP will affect the reinforcement effect, choosing reasonable longitudinal reinforcement interval of CFRP will make the reinforcement effect reach the optimum.

After strengthening CFRP, the circumferential stress value of the outer wall decreases obviously, and the reinforcing effect of CFRP is obvious.

It is an effective repairing method to reinforce steel pressure pipes by circular bonding of carbon fiber sheets. Especially for pipelines with defects, the circular stress of internal pressure pipes can be effectively reduced.