US3818752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for testing tightness
Assignee: Individual
•
Filing: 1972-04-20
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Granted: 1974-06-25
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Expires: 1992-04-20
Abstract
Abstract Method and apparatus for testing the air tightness of an enclosed chamber. A reference pressure is established in a control section isolated from the chamber, after which the chamber and control section are placed in communication with each other, creating an initial flow through a flow restricting valve in the control section. After the pressure difference across this valve falls below a predetermined valve, any further flow that is sensed is indicative of a leak in the chamber.
Inventors
- 👤 N Lindeberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:14
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/26; G01M3/32; G01M3/3236; G01M3/3254
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
223 words
A method for testing the air tightness of an enclosed chamber such as a tank, reservoir, pipe or the like, comprising the steps of: establishing a regulated reference pressure other than atmospheric pressure in a control section which is fluid isolated from the enclosed chamber and which includes a main conduit having a flow restricting valve openable in a flow direction only after a predetermined pressure drop thereacross and a flow meter connected in parallel across the flow restricting valve for sensing flow in said flow direction at a pressure drop across the meter smaller than said predetermined pressure drop, this establishing step including maintaining a continuous flow of fluid through at least part of the control section, placing the enclosed chamber and the control section into fluid communIcation with each other such that fluid flowing between the chamber and the control section initially flows in said flow direction through the flow restricting valve while the pressure drop across the flow restricting valve is greater than said predetermined pressure, after which the pressure drop across the flow restricting valve falls below the said predetermined pressure drop, whereupon the flow restricting valve closes, and sensing any further flow between the enclosed chamber and the control section across the flow meter, said further flow, if any, being indicative of a leak in the enclosed chamber.
Claim 2
Independent Claim
223 words
A method for testing the air tightness of an enclosed chamber such as a tank, reservoir, pipe or the like, comprising the steps of: establishing a regulated reference pressure other than atmospheric pressure in a control section which is fluid isolated from the enclosed chamber and which includes a main conduit having a flow restricting valve openable in a flow direction only after a predetermined pressure drop thereacross and a flow meter connected in parallel across the flow restricting valve for sensing flow in said flow direction at a pressure drop across the meter smaller than said predetermined pressure drop, this establishing step including maintaining a continuous flow of fluid through at least part of the control section, placing the enclosed chamber and the control section into fluid communIcation with each other such that fluid flowing between the chamber and the control section initially flows in said flow direction through the flow restricting valve while the pressure drop across the flow restricting valve is greater than said predetermined pressure, after which the pressure drop across the flow restricting valve falls below the said predetermined pressure drop, whereupon the flow restricting valve closes, and sensing any further flow between the enclosed chamber and the control section across the flow meter, said further flow, if any, being indicative of a leak in the enclosed chamber.
Claim 3
Dependent Claim
69 words
A method according to claim 1, in which the main conduit inludes a close valve between the control section and the enclosed chamber, and wherein the enclosed chamber is isolated by closing the close valve while the reference pressure is being established in the control section, and the step of placing the control section and the enclosed chamber into fluid communication with each other includes opening the close valve.
Claim 4
Dependent Claim
66 words
A method according to claim 2, wherein maintaining continuous flow in the control section prior to placing the control section and the enclosed chamber into communication with each other includes connecting a pump to a branch conduit having a pressure control valve, and regulating the pressure control valve with the close valve closed so that the pump subjects the main conduit to the said reference pressure.
Claim 5
Dependent Claim
28 words
A method according to claim 1, wherein said reference pressure is subatmospheric, and said flow direction is from the enclosed chamber through the control section to a pump.
Claim 6
Dependent Claim
61 words
A method according to claim 4, and including, after testing for leakage, the step of pressurizing the enclosed chamber to locate the leaks therein, wherein said pressurizing of the enclosed chamber is obtained by reversing the flow direction through the opened close valve and the main conduit into the enclosed chamber while keeping a constant flow direction through the control section.
Claim 7
Dependent Claim
39 words
A method according to claim 5 including regulating the pressure control valve so as to give a suitable overpressure to the control section before the enclosed chamber is subjected to said overpressure for the purpose of locating the leakage.
Claim 8
Independent Claim
278 words
An apparatus for testing the air tightness of an enclosed chamber such as a tank, reservoir, pipe or the like, comprising: a control section which includes a main conduit having a flow restricting valve openable in a flow direction only after a predetermined pressure drop thereacross and a flow meter connected in parallel across the flow restricting valve, said flow meter including means for indicating leakage in the enclosed chamber by sensing flow in said flow direction at a pressure drop across the meter smaller than said predetermined pressure drop, one end of said main conduit connected to the enclosed chamber by an openable and closable close valve which fluid isolates the enclosed chamber from the control section when it is closed, the other end of the main conduit connected to a means for establishing a reference pressure in the control section for maintaining a continuous flow of fluid through at least part of the control section, the relative flow characteristics of the flow restricting valve and of the flow meter being such that when the close valve is opened to place the enclosed chamber and the control section into fluid communication with each other, fluid flowing between the chamber and the control section which is at a pressure greater than said predetermined pressure, initially opens the flow restricting valve and flow in said flow direction through the flow restricting valve, and after the pressure drop across the flow restricting valve falls below the said predetermined pressure drop the flow restricting valve closes and any further flow between the enclosed chamber and the control section across the flow meter is indicative of a leak in the enclosed chamber.
Claim 9
Independent Claim
278 words
An apparatus for testing the air tightness of an enclosed chamber such as a tank, reservoir, pipe or the like, comprising: a control section which includes a main conduit having a flow restricting valve openable in a flow direction only after a predetermined pressure drop thereacross and a flow meter connected in parallel across the flow restricting valve, said flow meter including means for indicating leakage in the enclosed chamber by sensing flow in said flow direction at a pressure drop across the meter smaller than said predetermined pressure drop, one end of said main conduit connected to the enclosed chamber by an openable and closable close valve which fluid isolates the enclosed chamber from the control section when it is closed, the other end of the main conduit connected to a means for establishing a reference pressure in the control section for maintaining a continuous flow of fluid through at least part of the control section, the relative flow characteristics of the flow restricting valve and of the flow meter being such that when the close valve is opened to place the enclosed chamber and the control section into fluid communication with each other, fluid flowing between the chamber and the control section which is at a pressure greater than said predetermined pressure, initially opens the flow restricting valve and flow in said flow direction through the flow restricting valve, and after the pressure drop across the flow restricting valve falls below the said predetermined pressure drop the flow restricting valve closes and any further flow between the enclosed chamber and the control section across the flow meter is indicative of a leak in the enclosed chamber.
Claim 10
Dependent Claim
72 words
An apparatus according to claim 7, wherein the means for providing said reference pressure in the main conduit comprises a vacuum pump and including a branch conduit onto the suction side thereof including a flow indicator and on line therewith a pressure control valve for preregulating the pressure to be given by the vacuum pump to the enclosed chamber and for indicating a flow of idle flow air through the branch conduit.
Claim 11
Dependent Claim
28 words
An apparatus according to claim 7, wherein the flow-meter is interconnected with an electronic alarm system which includes means for indicating any present leakage in the enclosed chamber.
Claim 12
Dependent Claim
61 words
An apparatus according to claim 9, wherein the electronic alarm system comprises a photocell relay with a bulb emitting light rays and a photocell receiver positioned to receive such rays, and said photocell relay is so connected to the flow-meter and to the electronic alarm device that the alarm is activated as soon as a flow is present through the flow-meter.
Claim 13
Dependent Claim
36 words
An apparatus according to claim 7, wherein the fluid restricting valve is a one-way valve spring biased such that the valve opens upon a large pressure drop thereacross, while small flow amounts pass through the flow-meter.
Claim 14
Dependent Claim
33 words
An apparatus according to claim 7, including means for reversing the flow direction in the enclosed chamber for subjecting the interior of the enclosed chamber to an overpressure for facilitating locating leakages therein.
Claim 15
Dependent Claim
51 words
An apparatus according to claim 12, wherein the means for reversing the flow direction in the enclosed chamber comprises a system of valves which are so coupled that the flow direction through the control section and the pump is kept constant both during the vacuum testing and the subsequent pressure testing.
Claim 16
Dependent Claim
64 words
An apparatus according to claim 15, wherein the system of valves comprises two four-way valves which are connected to each other for movement together, and of which one valve is interconnected in the main conduit between the close valve and the adjacent connection point for the branch conduit with the flow-meter while the second valve is connected between the first valve and the pump.
Claim 17
Dependent Claim
99 words
An apparatus according to claim 14, wherein the main conduit is divided into four main conduit branches, in which the first main conduit branch forms a coil between two points of the first four-way valve and includes the fluid restricting valve means and the branch conduit, and in which the second main conduit branch forms a connection between the first four-way valve and the second four-way valve, the third main conduit branch forming a connection to the pump, and the fourth main conduit branch forming a connection between the pump and a connection point of the second four-way valve.
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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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |