US4706501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detection of step charges of pressure in vessels and apparatus therefor
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1981-11-09
•
Granted: 1987-11-17
•
Expires: 2001-11-09
Abstract
Abstract Detectors for monitoring step changes of pressure in a vessel, for example a pipeline, include sensors outside the vessel for detecting a change in its dimensions resulting from a fall in pressure occurring at a minimum rate of 0.005 bars per second which is not followed by a corresponding rise in pressure within 0.05 seconds. They are useful in detecting leaks.
Inventors
- 👤 Peter Atkinson
- 👤 Bernard D. Allan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:36
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0001; G01L9/0002; G01M; G01M3/00; G01M3/02; G01M3/26; G01M3/28; G01M3/2807; G01M3/283; G01M3/36
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
108 words
A detector for monitoring step changes of pressure in a vessel which comprises means outside the vessel for detecting a change in the dimensions of the vessel, said means being mounted on a jubilee clip for clamping around the vessel and said means being surrounded by a potting compound to protect it from moisture and impact; and a filter adapted to pass from the said means substantially only signals characteristic of dimensional changes resulting from a fall in pressure of the vessel occurring at a minimum rate of 0.005 bars per second which is not followed by a rise in pressure at that minimum rate within 0.05 seconds.
Claim 2
Dependent Claim
108 words
A detector for monitoring step changes of pressure in a vessel which comprises means outside the vessel for detecting a change in the dimensions of the vessel, said means being mounted on a jubilee clip for clamping around the vessel and said means being surrounded by a potting compound to protect it from moisture and impact; and a filter adapted to pass from the said means substantially only signals characteristic of dimensional changes resulting from a fall in pressure of the vessel occurring at a minimum rate of 0.005 bars per second which is not followed by a rise in pressure at that minimum rate within 0.05 seconds.
Claim 3
Dependent Claim
21 words
A detector as claimed in claim 1 in which the filter passes only signals in the range 0.1 to 4 Hertz.
Claim 4
Dependent Claim
19 words
A detector as claimed in claim 2 which comprises four or more strain gauges positioned diametrically opposite one another.
Claim 5
Dependent Claim
16 words
A detector as claimed in claim 2 which comprises strain gauges surrounded by an electrostatic shield.
Claim 6
Dependent Claim
40 words
A detector as claimed in claim 1 in which the means outside the vessel for detecting a change in the dimensions of the vessel comprises one or more strain gauges adapted to sense changes in the circumference of the vessel.
Claim 7
Dependent Claim
10 words
Vessels comprising detectors for leaks as claimed in claim 1.
Claim 8
Dependent Claim
118 words
Apparatus for detecting leaks in pipelines which comprises two or more detectors each including means outside the pipeline for detecting a change in the dimensions of the pipeline and a filter adapted to pass from said means substantially only signals characteristic of dimensional changes resulting from a fall in pressure in the pipeline occurring at a minimum rate of 0.005 bars per second which is not followed by a rise in pressure at that minimum rate within 0.05 seconds, said detectors being situated at successive stations along the pipeline; and means for processing signals from both detectors and for producing a signal indicating the position of a leak in response to the time relationship between the detected signals.
Claim 9
Dependent Claim
118 words
Apparatus for detecting leaks in pipelines which comprises two or more detectors each including means outside the pipeline for detecting a change in the dimensions of the pipeline and a filter adapted to pass from said means substantially only signals characteristic of dimensional changes resulting from a fall in pressure in the pipeline occurring at a minimum rate of 0.005 bars per second which is not followed by a rise in pressure at that minimum rate within 0.05 seconds, said detectors being situated at successive stations along the pipeline; and means for processing signals from both detectors and for producing a signal indicating the position of a leak in response to the time relationship between the detected signals.
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) | 1990-11-16 | 1991-05-18 | 1991-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-16 | 1995-05-18 | 1995-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-16 | 1999-05-18 | 1999-11-17 | $7700.00 | Window Closed / Lapsed |