US4130301A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double-walled well casing structure
Assignee: Kawasaki Thermal Systems Inc
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Filing: 1977-12-13
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Granted: 1978-12-19
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Expires: 1997-12-13
Abstract
Abstract A double-walled well casing for use in containing a fluid which is hotter than the ambient. The cavity between the double walls may contain insulation. Seals which maintain the inner and outer pipes in concentric relationship are designed to relieve the axial compressive stress on the inner pipe (resulting from thermal expansion relative to the outer pipe) by being stressed beyond their yield points.
Inventors
- 👤 Harry J. Dunham
- 👤 Gordon P. Hurd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:05
CPC Classifications
F; F16; F16L; F16L59/00; F16L59/14; F16L59/16; F16L59/18; E; E21; E21B; E21B17/00; E21B36/00; E21B36/003; F16L59/181
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A double-walled well casing structure for use in a working environment where the casing will carry a fluid which is hotter than the ambient temperature comprising: concentric inner and outer pipe sections; seal means at both ends of each pipe section sealing the cavity between said inner and outer pipes and supporting said pipes relative to each other; and said seal means constructed of metal and sized so that it will be stressed beyond its yield point by the differential thermal expansion of the inner and outer pipes relative to each other when in their working environment.
Claim 2
Dependent Claim
97 words
A double-walled well casing structure for use in a working environment where the casing will carry a fluid which is hotter than the ambient temperature comprising: concentric inner and outer pipe sections; seal means at both ends of each pipe section sealing the cavity between said inner and outer pipes and supporting said pipes relative to each other; and said seal means constructed of metal and sized so that it will be stressed beyond its yield point by the differential thermal expansion of the inner and outer pipes relative to each other when in their working environment.
Claim 3
Dependent Claim
17 words
A double-walled well casing in accordance with claim 1 wherein: said seal means has a concave configuration.
Claim 4
Dependent Claim
23 words
A double-walled well casing in accordance with claim 1 wherein: said cavity between said inner and outer pipes contains a heat insulating material.
Claim 5
Dependent Claim
42 words
A double-walled well casing in accordance with claim 1 further including: a flexible annular ring; said seal means having a concave configuration for receiving, together with the adjoining pipe section, said flexible annular ring; and coupling means for joining pipe sections together.
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) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |