Prevention of shear fracture in the natural gas pipelines is one of the most important problems for the safety of the natural gas transportation. The present paper gives a prediction method for the crack propagation and arrest in the ultra-high pressure pipelines, which is the recent trend of the pipeline design, and the toughness requirements for the high-grade line pipes to avoid the fracture. The prediction for crack propagation velocity and distance of the propagating shear fracture is enabled for any operating pressure, any grade of line pipes used and any compositions of natural gas for transmission. For the fracture safety of the ultra-high pressure pipelines, the followings are concluded. The increase of the operating pressure of the pipelines is not necessarily unsafe for the propagating shear fracture. The gas escape from the fractured portion is accelerated even in dual-phase decompression, and the effect of the pipe sizes can act for easy crack arrest in ultra-high pressure pipelines. Charpy requirements can be given for the grades and the sizes of the line pipes used. High-grade pipes such as X100 can be used safely for ultra-high pressure pipelines as far as the appropriate design stress and pipe sizes are selected. The smaller diameter and the thicker wall thickness are preferable for the short crack arrest of the propagating shear fracture. The positive proof of the prediction is left for future work. Full-scale burst tests are required for the ultra-high pressure pipelines. (VDEh)
Prediction for crack propagation and arrest of shear fracture in ultra-high pressure natural gas pipelines
Vorhersage der Rissausbreitung und des Scherbruchaufhaltevermögens in Ultrahochdruck-Erdgaspipelines
ISIJ International ; 41 , 4 ; 381-388
2001
8 Seiten, 17 Bilder, 4 Tabellen, 7 Quellen
Aufsatz (Zeitschrift)
Englisch
Fracture propagation - 1. Fracture-arrest prediction requires correction factors
Tema Archiv | 2008
|Fracture arrest assessment of low toughness pipelines
Tema Archiv | 2007
|A theoretical analysis of shear fracture propagation in backfilled gas pipelines
Tema Archiv | 1974
|