Sensor module for use in system for inspecting in-service gas distribution mains
US6198277A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1998 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Jun 26, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/83
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for inspecting in-service gas distribution mains is disclosed. Coiled tubing technology and magnetic flux leakage (MFL) technology are integrated to produce a new inspection system for low pressure, in-service distribution pipelines. The coiled tubing provides the means by which an inspection module employing MFL technology is inserted into, moved through, and removed from an in-service pipeline. A portable inspection system can thereby be moved to a desired location on a trailer. The sensor module comprises a plurality of magnet assemblies each having a Magnet N out, a Magnet S out and a magnet core, the magnet assemblies being conical in shape and being arranged into a circular array. The magnet array diameter is smaller than that of a pipe to be inspected, thus defining a radial air gap. The magnet array being constructed and arranged to provide a magnetic circuit having sufficient strength so as to be operable through the radial air gap. A centering mechanism is constructed and arranged to maintain the sensor module in concentric relation with the pipe to be inspected. This array provides an efficient method of packing the magnets to generate the very powerful magnetic…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.