Patent US4615477A successfully refreshed from Google Patents.
US4615477A
Expired / Lapsed
US
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Method for replacing tubes in a header or drum
Assignee: McDermott Technology Inc
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Filing: 1984-04-27
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Granted: 1986-10-07
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Expires: 2004-04-27
Abstract
Abstract A method for replacing tubes in a drum or header without removing the whole tube entirely is disclosed. According to the method, the old tube is cut off level with the header-member; a recess coterminous with the diameter of the tube is machined into the header creating a seat for a new tube; the recessed old tube end is beveled and the old tube is welded into the header-member along the bevel; and a new tube is inserted into the seat and welded to the exterior of the header-member. In a preferred embodiment, a countersink is machined in the surface of the header-member to create a greater surface for welding of the new tube.
Inventors
- 👤 Ralph E. Spada
- 👤 Thomas Shilot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:11
CPC Classifications
F; F28; F28F; F28F9/00; F16; F16L; F16L41/00; F16L41/08; F16L41/082; F16L41/084; F22; F22B; F22B37/00; F22B37/02; F22B37/10; F22B37/104; F28F11/00; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49718; Y10T29/49721; Y10T29/4973; Y10T29/49732; Y10T29/49734; Y10T29/49737
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
100 words
A method of repairing an old tube that penetrates beyond the wall thickness of a wall of a header-member comprising: (a) severing the old tube to form a cut end proximate the header-member; (b) machining the cut end of the old tube to form a recess and recessed tube end within the wall thickness of the header-member; (c) welding the recessed old tube end within the wall thickness to the header-member; (d) inserting an end of a new tube into the recess within the header-member proximate the recessed old tube end; and (e) welding the new tube to the header-member.
Claim 2
Independent Claim
100 words
A method of repairing an old tube that penetrates beyond the wall thickness of a wall of a header-member comprising: (a) severing the old tube to form a cut end proximate the header-member; (b) machining the cut end of the old tube to form a recess and recessed tube end within the wall thickness of the header-member; (c) welding the recessed old tube end within the wall thickness to the header-member; (d) inserting an end of a new tube into the recess within the header-member proximate the recessed old tube end; and (e) welding the new tube to the header-member.
Claim 3
Dependent Claim
20 words
A method according to claim 1 wherein step (b) further includes forming a bevel on the recessed old tube end.
Claim 4
Dependent Claim
27 words
A method according to claim 2 wherein step (c) comprises laying a weld bead about said bevel such that said bevel is filled by said weld bead.
Claim 5
Dependent Claim
60 words
A method according to claim 1 further comprising the step of forming a countersink in the header-member for providing a greater area of exposed new tube for welding to the header-member and wherein the step of welding the new tube to the header-member comprises forming a bead of weld in the countersink circumferentially connecting the new tube to the header-member.
Claim 6
Dependent Claim
24 words
A method according to claim 2 wherein the angle of the bevel is in a range from about 15° to about 50° of arc.
Claim 7
Dependent Claim
35 words
A method according to claim 1 wherein step (e) further comprises forming a weld bead that is approximately conically shaped to increase the surface area of the new tube that is welded to the header-member.
Claim 8
Dependent Claim
34 words
A method according to claim 1 wherein step (e) further comprises abutting said old tube and said new tube and holding said new tube in a predetermined attitude during the welding of step (e).
Claim 9
Dependent Claim
56 words
A method according to claim 1 wherein step (e) further comprises maintaining a distance of from about 3/32 inch to about 1/4 inch between said old tube end and said new tube end during welding of step (e) to allow for the pull down effect from cooling shrinkage of the weld bead created in step (e).
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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) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |