US4583394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device and method for leak location
Assignee: Japan Atomic Energy Agency
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Filing: 1984-08-07
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Granted: 1986-04-22
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Expires: 2004-08-07
Abstract
Abstract A method and apparatus are disclosed for detecting the presence of very fine leaks through the walls of an enclosure which include a sniffer nozzle (1) open to the atmosphere, a vessel (5) having molecular sieves (4) therein for adsorbing substantially all gaseous products which have entered the sniffer nozzle (1) with the exception of the probe gas which has been pressurized within the enclosure being tested, a pump system (8, 9) for creating vacuum conditions within the system, a mass spectrometer (12) for detecting the presence of the probe gas, and a capillary tube (2) interconnecting the nozzle sniffer (1) and the molecular sieve assembly whereby the probe gas draw rate, and sensitivity of the apparatus of the present invention, are significantly increased.
Inventors
- 👤 Yoshio Murakami
- 👤 Kenjiroh Obara
- 👤 Tetsuya Abe
- 👤 Yasuo Shimomura
- 👤 Takemasa Shibata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:37
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/20; G01M3/202
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
162 words
A system for determining leaks through the walls of an enclosure which has been charged with a probe gas, comprising: vacuum suction means for establishing a source of vacuum within said system; means fluidically connected to said vacuum suction means for detecting the presence of said probe gas; nozzle means open to the atmosphere for disposition outside of said enclosure walls so as to capture said probe gas leaking out from said enclosure through leak locations within said enclosure walls; porous adsorbent means fluidically connected to said gas detecting means for adsorbing substantially all gaseous products which have entered said nozzle means yet permitting said probe gas to pass through said porous adsorbent means to said gas detecting means; and capillary tube means connected to said nozzle means and said porous adsorbent means for defining a high flow rate of said probe gas within said system whereby the sensitivity and leak detection efficiency of said system is able to be rendered high.
Claim 2
Independent Claim
162 words
A system for determining leaks through the walls of an enclosure which has been charged with a probe gas, comprising: vacuum suction means for establishing a source of vacuum within said system; means fluidically connected to said vacuum suction means for detecting the presence of said probe gas; nozzle means open to the atmosphere for disposition outside of said enclosure walls so as to capture said probe gas leaking out from said enclosure through leak locations within said enclosure walls; porous adsorbent means fluidically connected to said gas detecting means for adsorbing substantially all gaseous products which have entered said nozzle means yet permitting said probe gas to pass through said porous adsorbent means to said gas detecting means; and capillary tube means connected to said nozzle means and said porous adsorbent means for defining a high flow rate of said probe gas within said system whereby the sensitivity and leak detection efficiency of said system is able to be rendered high.
Claim 3
Dependent Claim
14 words
The system as set forth in claim 1 wherein said capillary tube is flexible.
Claim 4
Dependent Claim
20 words
The system as set forth in claim 1 wherein the inner diameter of said capillary tube is below 0.75 mm.
Claim 5
Dependent Claim
15 words
The system as set forth in claim 1 wherein said porous adsorbent is molecular sieves.
Claim 6
Dependent Claim
17 words
A system as set forth in claim 1, wherein: said capillary tube is fabricated from stainless steel.
Claim 7
Dependent Claim
17 words
A system as set forth in claim 1, wherein: said capillary tube is ten meters in length.
Claim 8
Dependent Claim
55 words
A system as set forth in claim 1, further comprising: enclosure sealing means disposed about said capillary tube means and engaging the exterior surface of said enclosure wall of said enclosure being tested for said leak locations so as to enclose said nozzle means therewithin; and inert atmospheric means defined within said enclosure sealing means.
Claim 9
Dependent Claim
17 words
A system as set forth in claim 7, wherein: said enclosure sealing means comprises a polyethylene bag.
Claim 10
Dependent Claim
16 words
A system as set forth in claim 7, wherein: said inert atmospheric means comprises pure nitrogen.
Claim 11
Dependent Claim
19 words
A system as set forth in claim 3, wherein: said inside diameter of said capillary tube is 0.6 mm.
Claim 12
Dependent Claim
16 words
A system as set forth in claim 1, wherein: said detecting means comprises a mass spectrometer.
Claim 13
Independent Claim
193 words
A method of detecting leak locations within the walls of an enclosure structure, comprising the steps of: charging the interior of said enclosure structure with a probe gas; establishing a source of vacuum for inducing a fluid flow; fluidically connecting a sniffer nozzle, open to the atmosphere, to said source of vacuum whereby an atmospheric fluid flow will be induced into said sniffer nozzle under the influence of said source of vacuum; fluidically interposing a capillary tube between said sniffer nozzle and said source of vacuum whereby a high fluid flow rate will be induced through said sniffer nozzle and said capillary tube under the influence of said vacuum source; interposing a probe gas detector between said capillary tube and said vacuum source; interposing porous adsorbent means between said probe gas detector and said capillary tube for adsorbing substantially all gaseous products induced into said sniffer nozzle yet permitting said probe gas to pass through said adsorbent means to said probe gas detector; and moving said sniffer nozzle along the outside wall surfaces of said enclosure structure for capturing any probe gas leaking out of said enclosure structure through a leak location thereof.
Claim 14
Independent Claim
193 words
A method of detecting leak locations within the walls of an enclosure structure, comprising the steps of: charging the interior of said enclosure structure with a probe gas; establishing a source of vacuum for inducing a fluid flow; fluidically connecting a sniffer nozzle, open to the atmosphere, to said source of vacuum whereby an atmospheric fluid flow will be induced into said sniffer nozzle under the influence of said source of vacuum; fluidically interposing a capillary tube between said sniffer nozzle and said source of vacuum whereby a high fluid flow rate will be induced through said sniffer nozzle and said capillary tube under the influence of said vacuum source; interposing a probe gas detector between said capillary tube and said vacuum source; interposing porous adsorbent means between said probe gas detector and said capillary tube for adsorbing substantially all gaseous products induced into said sniffer nozzle yet permitting said probe gas to pass through said adsorbent means to said probe gas detector; and moving said sniffer nozzle along the outside wall surfaces of said enclosure structure for capturing any probe gas leaking out of said enclosure structure through a leak location thereof.
Claim 15
Dependent Claim
14 words
A method as set forth in claim 12, wherein: said probe gas is helium.
Claim 16
Dependent Claim
19 words
A method as set forth in claim 12, wherein: the inside diameter of said capillary tube is 0.60 mm.
Claim 17
Dependent Claim
17 words
A method as set forth in claim 12, wherein: said capillary tube is fabricated from stainless steel.
Claim 18
Dependent Claim
17 words
A method as set forth in claim 12, wherein: said probe gas detector is a mass spectrometer.
Claim 19
Dependent Claim
15 words
A method as set forth in claim 12, wherein: said porous adsorbent comprises molecular sieves.
Claim 20
Dependent Claim
18 words
A method as set forth in claim 12, wherein: said capillary tube has a length of ten meters.
Claim 21
Dependent Claim
21 words
A method as set forth in claim 12, additionally comprising the steps of: enclosing said sniffer nozzle within an inert atmosphere.
Claim 22
Dependent Claim
15 words
A method as set forth in claim 19, wherein: said inert atmosphere is pure nitrogen.
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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) | 1989-04-21 | 1989-10-21 | 1990-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-21 | 1993-10-21 | 1994-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-21 | 1997-10-21 | 1998-04-22 | $7700.00 | Window Closed / Lapsed |