Line pipe, strength level

Type A sleeves simply encircle the pipeline and provide structural reinforcement of the defective area. To do this, they do not require sleeve-end fillet welds. Type B sleeves also encircle the pipeline and provide structural reinforcement, but since the ends are fillet welded to the pipeline, they can also contain pressure in the event that the defect is leaking or will eventually leak in subsequent service. The results of work at BatteUe showed that steel sleeve repairs are capable of restoring the strength of a damaged pipeline to a pressure level in excess of a pressure that corresponds to 100% of the specified minimum yield strength of the line pipe steel. The results of this work led to the widespread use of fuU-encirclement steel sleeves for pipeline... 

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