Page 61 - Reliability and Maintainability of In service Pipelines

50 Reliability and Maintainability of In-Service Pipelines

2.3 Inspection Methods 59
2.3.1 CCTV Method 59
2.3.2 Laser Scanning 62
2.3.3 Ultrasonic Intelligent Pigging 63
2.3.4 Magnetic Flux Leakage Technique 65
2.3.5 Radiographic Testing 67
2.3.6 Acoustic Detection 67
2.3.7 Ground Penetration Radar 69
2.3.8 Methods Overview 69
2.4 Pipeline Maintenance 69
2.4.1 Coatings 72
2.4.2 Cathodic Protection 73
2.4.3 Cleaning 74
2.4.4 Corrective Action 74
Symbols 75
References 77
Further Reading 78

2.1 Background

Pipeline infrastructures are valuable assets and therefore the inspection and con-
tinuous maintenance of pipes must be actively carried out in order to guarantee
the long service life and the best pipeline operation. Current literature in this field
has understood that the need for an automatic defect detection technology is nec-
essary since the use of human operators and manual inspection process is very
time-consuming and can only capture 60% 75% of data accurately without the
use of automated system in place. Although automated systems such as intelligent
pigging have been developed, further work and innovation must be undertaken in
order to create a complete automated inspection process that is able to be used in
pipeline networks accurately and produce reliable data on a consistent basis.
The reliability of a pipeline can be assessed using the data collected through
routine pipeline inspections. The reliability of a pipeline defines how well the
pipeline is functioning and how well it will remain functioning at its very best
without failure. Further explanation on pipeline reliability is found in Chapter 3,
Methods for Structural Reliability Analysis.
Corrosion is a major factor which decreases pipeline reliability. Thus monitor-
ing corrosion progress through inspection should be of more interest for pipeline
maintenance engineers.
Inspection can be more challenging for underground pipelines, as they are hid-
den without easy access for inspection. Many of these assets are approaching their