Pipes are of major importance for transport of liquids and gas mainly for water, natural gas and oil. In Western Europe, the distribution of drinking water has been achieved 20 years ago and the problem of renewal of the networks is now considered as an accurate question in terms of money and time. From the quantitative point of view, it has been shown that the quality of the networks is highly perfectible.
Total gas pipes length in the world is estimated to 1 million km for gas transport (pipes of diameter 80–1,000 mm). In China, the construction of the natural gas pipelines has gained its initial scale. The pipelines are of capital importance for the landlocked countries. Currently, only crude exports of Russia towards Europe completely depend on the pipelines.
The pipelines of long distance have a great geopolitical importance. It is the case, for instance, for the area of the Caspian Sea, where all the plans of export of oil starting from this area primarily depend on the construction of pipelines.
The pipeline remains the mean of transcontinental transport least expensive compared to the rail-bound or ground transport. It constitutes under this aspect an important mean of transport between the USA and Canada, but also between the various European countries where the pipelines are relatively of short distance.
It became increasingly paramount to ensure the safe utilisation of such pipelines in order to prevent economical, social and ecological losses. From a technical point of view, pipelines are complicated 3D structures that include straight pipes, nozzles, pipe-bends, dissimilar welded joints, etc. In addition, their operating conditions can be quite severe, that is, internal pressure and cyclic loading (vibration) combined with the influence of internal and external corrosive environments. The potential synergy of such parameters can lead to an increase in the risk of damage and unexpected fracture of these structures during their long-term exploitation.
Leak and fracture of pipes is assumed to be achieved by initiation and propagation of a defect and final failure when defect reaches a critical length. To have a precise idea of life duration of the water pipes the three following components need to be precisely described:
1. Defect initiation
2. Propagation
3. Final failure
This book presents papers, which were delivered at the NATO Workshop “Safety, reliability and risks associated with water, oil and gas pipelines” held in Helnan Palestine Hotel, Alexandria (Egypt), 4th–8th February 2007, under the auspices of the NATO Science for Peace and Security Program.
Three major defect assessment tools for pipes are presented:
(a) Failure assessment diagram and particularly the SINTAP
(b) Limit analysis
(c) Strain design approach
Repairing methods are based on results of investigation. Methods such as welded sleeve, clamped composite sleeve, grinding and pipe replacement are described.
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Originally Posted by f81aa
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