US4606491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for sealing a leak in a rolled tube/tubeplate joint
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1984-12-27
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Granted: 1986-08-19
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Expires: 2004-12-27
Abstract
Abstract The process steps for sealing a leak in rolled tube/tubeplate joints in heat exchange units comprise removing a portion of the tube end (2) and of the tube-plate (1) by a milling cut (6) and joining the surfaces thus formed by a weld seam (7) of preferably lens-shaped cross-section.
Inventors
- 👤 Son Le Mong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:10
CPC Classifications
F; F28; F28F; F28F11/00; B; B23; B23K; B23K9/00; B23K9/02; B23K9/028; B23K9/0288; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49352; Y10T29/49718; Y10T29/49746; Y10T29/49748
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
202 words
Process for sealing a leak in a rolled tube/tubeplate joint, in which the end (2; 3) of a heat exchanger tube is non-positively fixed in a hole in a tubeplate (1), serving as a partition in a heat exchange unit, by radial expansion by means of a rolling-in tool with pressure prestressing, the leak being eliminated by welding, characterized in: (a) that, at the end face of the tube end (1; 2), a milling cut (6) is made which is coaxial to the longitudinal axis of the heat exchanger tube and the diameter (D E ) of which is greater by substantially twice the wall thickness (s) of the heat exchanger tube than the external diameter (D) of the latter, so that an annular portion is milled out of the tubeplate around the tube end; (b) that the end face of the tube end (1; 2) is joined by a weld seam (7) to the surface formed by the milling cut (6) in the tubeplate (1); (c) that the weld seam (7) is made with a lens-shaped cross-section; and (d) that the depth (t) of the milling cut (6) is substantially equal to the wall thickness (s) of the heat exchanger tube.
Claim 2
Dependent Claim
202 words
Process for sealing a leak in a rolled tube/tubeplate joint, in which the end (2; 3) of a heat exchanger tube is non-positively fixed in a hole in a tubeplate (1), serving as a partition in a heat exchange unit, by radial expansion by means of a rolling-in tool with pressure prestressing, the leak being eliminated by welding, characterized in: (a) that, at the end face of the tube end (1; 2), a milling cut (6) is made which is coaxial to the longitudinal axis of the heat exchanger tube and the diameter (D E ) of which is greater by substantially twice the wall thickness (s) of the heat exchanger tube than the external diameter (D) of the latter, so that an annular portion is milled out of the tubeplate around the tube end; (b) that the end face of the tube end (1; 2) is joined by a weld seam (7) to the surface formed by the milling cut (6) in the tubeplate (1); (c) that the weld seam (7) is made with a lens-shaped cross-section; and (d) that the depth (t) of the milling cut (6) is substantially equal to the wall thickness (s) of the heat exchanger tube.
Claim 3
Dependent Claim
36 words
Process according to claim 1, characterised in that the joint between the periphery of the tube end (2; 3) and the tubeplate (1) is blown with superheated steam and the blown area is dried before welding.
Claim 4
Dependent Claim
125 words
A process for sealing a leak in a rolled tube/tubeplate joint, said process comprising the steps of: (a) milling a cut: (i) which is coaxial to the longitudinal axis of the tube; (ii) the diameter of which is greater by at least substantially twice the wall thickness of the tube than the external diameter of the tube; and (iii) the depth of which is at least substantially equal to the wall thickness of the tube, thereby forming an annular, inwardly stepped face composed of the end of the tube and the adjacent surface of the tubeplate, and (b) welding the end of the tube to the adjacent surface of the tubeplate in the annular, inwardly stepped face with a weld seam having a lens-shaped cross-section.
Claim 5
Dependent Claim
125 words
A process for sealing a leak in a rolled tube/tubeplate joint, said process comprising the steps of: (a) milling a cut: (i) which is coaxial to the longitudinal axis of the tube; (ii) the diameter of which is greater by at least substantially twice the wall thickness of the tube than the external diameter of the tube; and (iii) the depth of which is at least substantially equal to the wall thickness of the tube, thereby forming an annular, inwardly stepped face composed of the end of the tube and the adjacent surface of the tubeplate, and (b) welding the end of the tube to the adjacent surface of the tubeplate in the annular, inwardly stepped face with a weld seam having a lens-shaped cross-section.
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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |