Pipeline corrosion detection is an important maintenance link to ensure the safety and efficiency of the pipeline system. Inspection methods range from simple visual inspection to sophisticated non-destructive testing techniques. Here are some common pipe corrosion detection methods:
Visual inspection：
This is the most basic way of detecting, by observing the exterior of the pipe for signs of corrosion, such as rust, blistering, peeling, etc. with the naked eye.
Electrochemical corrosion monitoring：
Electrodes are placed on the surface of the pipe and changes in current and potential are monitored to judge corrosion.
Acoustic wave detection：
The pipeline is scanned with ultrasonic testing instruments, and the thinning of the pipeline wall thickness or other structural changes are identified by analyzing the echo signals.
Multifrequency Current Mapping System (PCM)：
A technique for locating and evaluating coating conditions and corrosion activity in underground pipes.
Standard Tube Ground Potential (P/S) Test：
The potential difference between the pipe and the surrounding soil was measured to evaluate the cathodic protection effect.
Closely spaced potential test technique (CIS)：
The potential along the pipe was measured in detail to determine the performance of the cathodic protection system.
Pearson test：
Another test method for assessing the status of cathodic protection, usually used in conjunction with PCM.
Cathodic Protection Current Test (CPS)：
The cathodic protection current flowing through the pipeline is measured directly to evaluate the effectiveness of the protection system.
DC Potential Gradient Test (DCVG)：
Locate coating breakage and corrosion hotspots by detecting voltage gradients around the pipe.
Penetration detection：
The penetrant was applied to the surface of the pipe and defects and cracks were revealed by the developer.
Infrared thermal imaging detection：
Identify possible corrosion or leak points by detecting temperature differences on the surface of the pipe.
Corrosion Monitoring in Pipeline：
Use a pig or a smart detection tool, such as a magnetic flux leakage detector, to perform non-destructive testing inside the pipe.
Hydrogen flow measurement：
The flow rate of hydrogen was measured under specific conditions to evaluate the corrosion rate.
Each inspection method has its applicable scenarios and limitations, and it is often necessary to synthesize multiple technologies in practical applications to obtain a more comprehensive pipeline health assessment. The selection of the appropriate inspection method depends on the specific conditions of the pipeline, the environment in which it is located, the type of corrosion, and the purpose of the inspection.