US3835324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pipe weld inspection method and apparatus
Assignee: Individual
•
Filing: 1972-10-04
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Granted: 1974-09-10
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Expires: 1992-10-04
Abstract
Abstract An illustrative embodiment of the invention includes method and apparatus for pipe weld seam inspection. A gamma ray source of relatively low intensity is disposed on the interior portion near the center of a pipe section being inspected. A gamma ray detector comprising an activated scintillating crystal and a photomultiplier tube is traversed in a track on an elastomeric belt about the circumference of the pipe and maintained adjacent said weld seam at all circumferential points. The intensity of the gamma radiation penetrating the weld seam is sensed and recorded as a function of the circumferential location of the detectors. This recording may then be interpreted in terms of the material density of the weld at all circumferential points on the seam.
Inventors
- 👤 O Weigle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:03
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/06; G01N23/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
136 words
Apparatus for inspecting weld seams in pipe lines for defects, comprising: means, disposed substantially at the center of the interior portion of a pipe section, for emitting gamma radiation; radiation detector means disposed adjacent the weld seam to be inspected on the exterior of the pipe section for detecting gamma radiation penetrating said weld seam; means for moving said radiation detector means at a constant speed circumferentially about the exterior portion of a pipe section and including elastomeric track means disposed circumferentially about said pipe section being inspected and disposed approximately longitudinally equidistant at all circumferential points from said weld seam for guiding said means for moving said radiation detector; and means for counting and recording signals developed by said detector means as a function of the circumferential position of said detector means on said pipe.
Claim 2
Dependent Claim
136 words
Apparatus for inspecting weld seams in pipe lines for defects, comprising: means, disposed substantially at the center of the interior portion of a pipe section, for emitting gamma radiation; radiation detector means disposed adjacent the weld seam to be inspected on the exterior of the pipe section for detecting gamma radiation penetrating said weld seam; means for moving said radiation detector means at a constant speed circumferentially about the exterior portion of a pipe section and including elastomeric track means disposed circumferentially about said pipe section being inspected and disposed approximately longitudinally equidistant at all circumferential points from said weld seam for guiding said means for moving said radiation detector; and means for counting and recording signals developed by said detector means as a function of the circumferential position of said detector means on said pipe.
Claim 3
Dependent Claim
39 words
The apparatus of claim 1 wherein said counting and recording means includes integrator means and chart recorder means for providing a visual record of said detector means signals as a function of the circumferential position of said detector means.
Claim 4
Dependent Claim
23 words
The apparatus of claim 1 wherein said radiation detector means comprises a thallium activated sodium iodide crystal optically coupled to a photomultiplier tube.
Claim 5
Dependent Claim
22 words
The apparatus of claim 1 wherein said radiation detector means comprises an activated cesium iodide crystal optically coupled to a photomultiplier tube.
Claim 6
Dependent Claim
16 words
The apparatus of claim 1 wherein said radiation source does not exceed 500 millicuries in intensity.
Claim 7
Independent Claim
138 words
A method of inspecting pipe weld seams for welding defects comprising the steps of: emitting gamms radiation from a gamma ray source located substantially at the interior center of a pipe section being inspected; detecting, at a point substantially adjacent said weld seams being inspected, gamma radiation from said source which have penetrated said weld seam and generating pulse signals representative thereof; repeating said detecting step at all circumferential points adjacent said weld seam on said pipe section by moving a scintillation type radiation detector at a constant speed about the circumference of said pipe in an elastomeric track means disposed circumferentially about said pipe and disposed approximately longitudinally equidistant at all circumferential points from said weld seam; and recording output signals representative of said representative pulse signals as a function of the circumferential locations of said detector.
Claim 8
Independent Claim
138 words
A method of inspecting pipe weld seams for welding defects comprising the steps of: emitting gamms radiation from a gamma ray source located substantially at the interior center of a pipe section being inspected; detecting, at a point substantially adjacent said weld seams being inspected, gamma radiation from said source which have penetrated said weld seam and generating pulse signals representative thereof; repeating said detecting step at all circumferential points adjacent said weld seam on said pipe section by moving a scintillation type radiation detector at a constant speed about the circumference of said pipe in an elastomeric track means disposed circumferentially about said pipe and disposed approximately longitudinally equidistant at all circumferential points from said weld seam; and recording output signals representative of said representative pulse signals as a function of the circumferential locations of said detector.
Claim 9
Dependent Claim
31 words
The method of claim 6 wherein said signals are recorded in other than a 1:1 dimensional relationship with the circumferential location of the measurement on the pipe weld seam being inspected.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |