Abstract: A method of hydrostatic testing a selected section of a pipeline having fluid flow therethrough, including the steps of introducing into the pipeline a pig train including a leading seal pig, a supply liquid slug, a first isolation tool, a test liquid slug and a second isolation tool; permitting the train to traverse the pipeline interior by the force of fluid flow until the lead isolation tool is forwardly of and the second isolation tool is rearwardly of the selected selection of the pipeline; securing the position of the pig train by applying exteriorly of the pipeline appropriate signals to actuate the isolation tools to each engage and seal the interior of the pipeline trapping the test liquid slug therebetween; and pumping liquid from the supply liquid slugs into the test liquid slug to a hydrostatic testing pressure. In addition to testing, the pipeline can be repaired by moving the pig train into position where a defective area can be isolated by additional isolation tools.

Abstract: A pipeline pig having improved means of sensing changes in the internal configuration of the pipeline through which the pig passes is provided by the invention which employs a pipeline pig body, a radial cup of elastomeric material supported to the body having a circumferential edge which engages the interior of the pipeline, a longitudinally positionable stylus shaft supported coaxially of the body and the cup, the inner end of the shaft providing means to actuate an instrumentation recording device, a transfer plate affixed in a radial manner to the outer end of the shaft rearwardly of the cup, and a plurality of spaced apart sensor members, each formed of a metal rod, the inner end of each of the sensor members being affixed to the body and the outer ends being affixed to the transfer plate, the intermediate portion of the sensor members having an integral coil portion which resiliently deflects the outer ends outwardly, the coil engaging the inner circumferential surface of the cup lip portion so that as

Abstract: An improved pig for use in a pipeline is provided in which the basic structure including a body and the cup portions integrally formed of a unitary design, the body being of an elongated cylindrical configuration, including at least a forward and rearward cup extending from the body, the diameter of the cups being at least two and not more than five times the diameter of the body, the normal diameter of the cups in non-used condition being slightly greater than the internal diameter of the pipeline for which the pig is dimensioned and the length of the body being at least 11/2times the normal diameter of the cups. In a preferred arrangement the body is hollow or tubular for a substantial portion of its length and has an insert of a tubular rigid material; the thickness of the cups is less adjacent the body and the increases in thickness towards the peripheral surface; and the rearward cup has pressure equalizing openings.

Abstract: A pipeline pig is provided which is especially adapted for use in conjunction with laying offshore pipelines in that it detects and indicates dents, and other disconformities in the nominal cross-sectional configuration of the pipeline which may occur as a result of the laying of the pipeline. It employs a plurality of prolate spheroid rollers arranged to secure substantially full circle coverage of the pipeline and yet only a minor portion of the length of the rollers will be normally in contact with the pipeline thereby reducing the wear on the remaining portions of the rollers and increasing the ease with which the pig can be towed along the pipeline. In another aspect, a system is provided in which a pig includes with a means of sensing a condition along the pipeline and a memory means for storing the output of the detecting means.