Pii Limited

Peter Allan Couchman

Ian D Smith

David Carl Maughan

Brian Kenneth Jones

In an in-line pipe inspection tool, sensors for inspecting the pipe are mounted on sensor blocks moveable relative to the body of the tool. However, when the sensor blocks move radially to conform to different pipe diameters, the circumferential distances between the sensors changes. To ameliorate the effect of this, the sensor blocks have a shape such that one axial edge of each sensor block circumferentially overlaps the opposite edge of an adjacent sensor block. With such an arrangement, when the sensor block are operating at minimum diameter, part of one sensor block will overlap an adjacent block, in the circumferential direction. As the diameter of the pipeline in which the pig is used increases, the degree of overlap will reduce, and may even reduce to zero, but there will still be no overall axial gaps between the sensor blocks. Thus, by suitable shaping of the sensor blocks the tool can be used with a wide range of pipe diameters.

Sensor system for an in-line inspection tool

A pipeline pig includes a central body member, a plurality of circumferentially spaced return path elements surrounding said body member and each extending axially relative to the body member, each return path element including a pair of axially spaced magnets from each of which projects a metallic bristle set, and means for connecting the return path elements to the body member whereby the free ends of the bristles, in use, resiliently engage the inner wall of the pipeline, the connecting means comprising a first carrier member mounted on, to be axially slidable relative to, the front extent of the body member and resiliently urged towards the rear of the body member, a second carrier member mounted on, to be axially slidable relative to, the rear extent of the body member and resiliently urged towards the front of the body member, and, for each return path element, a front link pivotally interconnecting the front of the return path element and the first carrier member, and a rear link pivotally interconnecting the rear of the return path element and the second carrier member.

Pipeline pigs

A pipeline pig comprises a body and at least one flexible annular outwardly extending seal on and around the body for sealingly contacting a pipeline interior wall under differential fluid pressure whereby to propel the pig along the pipeline. The pig also comprises a fluid bypass duct arrangement extending through the body and resilient frictional bristles on and extending from the body adapted to contact the pipeline interior wall and exert a drag on the pig. An adjustable bypass flow control unit is provided which is adapted to regulate fluid flow through the duct arrangement and thus the speed of the pig.

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Newcastle upon Tyne, United Kingdom

Peter Allan Couchman