Patent US4189938A successfully refreshed from Google Patents.
US4189938A
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Double tracer gas process for locating conduit leaks
Assignee: Heath Consultants Inc
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Filing: 1978-12-13
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Granted: 1980-02-26
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Expires: 1998-12-13
Abstract
Abstract A process for locating leaks in an underground protective conduit disposed about a carrier pipe, and comprising the insertion of a double tracer gas into the protective conduit for the purpose of detecting leaks in the protective conduit. The process comprises the use of a double tracer gas which includes about two and one-half (21/2) to ten (10) percent methane and about ninety (90) to ninety-seven and one-half (971/2) percent argon.
Inventors
- 👤 Paul M. Heim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:18
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/20; G01M3/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
103 words
A double tracer gas process for locating conduit leaks in a conduit, comprising the steps of: (a) inserting a double tracer gas comprising a mixture of a lighter than air gas which will rise to the surface from a leak in the conduit and be vented to the atmosphere, and a heavier than air gas which will escape from a leak in the conduit into the sub-surface atmosphere around the conduit; (b) detecting the leakage of the lighter than air hydrocarbon gas by a flame ionization detector; and, (c) detecting the leakage of the heavier than air gas by a gas detection means.
Claim 2
Dependent Claim
103 words
A double tracer gas process for locating conduit leaks in a conduit, comprising the steps of: (a) inserting a double tracer gas comprising a mixture of a lighter than air gas which will rise to the surface from a leak in the conduit and be vented to the atmosphere, and a heavier than air gas which will escape from a leak in the conduit into the sub-surface atmosphere around the conduit; (b) detecting the leakage of the lighter than air hydrocarbon gas by a flame ionization detector; and, (c) detecting the leakage of the heavier than air gas by a gas detection means.
Claim 3
Dependent Claim
37 words
A double tracer gas process for locating conduit leaks in a conduit as defined in claim 1, wherein: (a) said lighter than air gas comprises methane gas; and, (b) said heavier than air gas comprises argon gas.
Claim 4
Dependent Claim
40 words
A double tracer gas process for locating conduit leaks in a conduit as defined in claim 2, wherein: (a) said double tracer gas comprises a mixture of about 21/2% to 10% methane gas and about 90% to 971/2% argon gas.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |