{"product_id":"l51671-criteria-for-dent-acceptability-of-offshore-pipelines-1","title":"L51671 Criteria for Dent Acceptability of Offshore Pipelines","description":"\u003cp\u003eExtensive research has provided an understanding in the behavior of pipelines subjected to mechanical damage. The presence of a gouge or the combination of a gouge and a dent has been proven detrimental to the burst strength of pipelines. The research has also revealed that plain smooth dents, in the absence of a defect, do not significantly reduce the burst strength of pipelines. On the other hand, plain dents locally increase the pipe stress due to pressure. Thus, fatigue failures from dents can occur from normal operating pressure fluctuations in the lines over a period of time This report documents the testing and analysis work done to establish the effects of pipeline dents (without gouges) under cyclic internal pressure loading. The work consisted of several sub-tasks. First, operators were surveyed regarding the expected dent shapes and failures from dents that had been experienced. Secondly, a full scale test program utilizing 12-3\/4\" pipe was carried out. In this program eight pipes, each 20\" long with diameter\/thickness ratios of 18-50, were subjected to three dents each of various sizes and pressure cycled until failure or until 50,000 to 70,000 equivalent cycles of 0 - 1200 psi pressure was achieved. Next, elastic finite element analysis was utilized to determine the significance of dent shapes and lengths. Finally plastic finite element analysis was utilized to determine analytically the stress to pressure ratios so that a fatigue analysis could be done.\u003c\/p\u003e","brand":"PRCI Store","offers":[{"title":"Default Title","offer_id":44367621226574,"sku":"15321","price":495.0,"currency_code":"USD","in_stock":true}],"url":"https:\/\/prci-store.myshopify.com\/products\/l51671-criteria-for-dent-acceptability-of-offshore-pipelines-1","provider":"PRCI Store","version":"1.0","type":"link"}