Pressure-testing method permits line-segment isolation

This paper reports that pressure or leak testing a segment of a pipeline is now possible by use of a pressure-testing tool that isolates a locally disturbed area of the line. The system avoids the potentially expensive alternative of decommissioning an entire length of line for pressure testing. High-pressure pipes and pipelines are essential for hydrocarbon production, processing, and transportation. For safety reasons, procedures need to be established and implemented during construction and maintenance which ensure the continued operation of a plant or pipeline. These procedures often call for high-pressure hydrostatic or leak testing. Although only small elements of a pressure system may be disturbed, it has been necessary on occasion to carry out extensive pressure testing for an entire system. This can, for example, involve the testing of many miles of pipe in a pipeline system or the total flooding of pipework which has previously been maintained dry. The new system can be used to test only a locally disturbed area and provides an efficient and cost-effective means of either hydrostatic or leak testing welds, spurs, flanges, and valves. The pressure-test media can include any of the following: water, glycol, nitrogen, or nitrogen/helium mix.