US3769489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Welding of tubes to tube plates
Assignee: Robert Jenks & Co Ltd
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Filing: 1971-12-29
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Granted: 1973-10-30
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Expires: 1991-12-29
Abstract
Abstract A method of welding tubes to tube plates of heat exchangers, including a weld preparation which involves counterboring the end of each tube either before or after it is entered into a hole in the tube plate so that the molten ''''pool'''' of metal during the subsequent welding operation is as small as possible and so that the direction in which the arc is struck between the welding electrode and tube is stabilised.
Inventors
- 👤 E Charlesworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:25
CPC Classifications
F; F28; F28F; F28F9/00; F28F9/02; F28F9/04; F28F9/16; F28F9/18; B; B23; B23K; B23K9/00; B23K9/02; B23K9/028; B23K9/0288; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49373
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A method of welding a tube to a tube plate, comprising at least the steps of counterboring the end of a tube to produce a reduced thickness wall adjacent the tube end, entering at least said end into a mating hole in the tube plate, positioning a nonconsumable electrode within the counterbore, and rotating the electrode around within said counterbore and spaced apart from said wall while applying an arc inducing current thereto so that the arc which is produced between the electrode and the adjacent surface of said counterbore generates sufficient heat in said reduced thickness wall and the region of said tube plate surrounding such mating hole in which the tube touches the tube plate as to form a weld therebetween.
Claim 2
Independent Claim
123 words
A method of welding a tube to a tube plate, comprising at least the steps of counterboring the end of a tube to produce a reduced thickness wall adjacent the tube end, entering at least said end into a mating hole in the tube plate, positioning a nonconsumable electrode within the counterbore, and rotating the electrode around within said counterbore and spaced apart from said wall while applying an arc inducing current thereto so that the arc which is produced between the electrode and the adjacent surface of said counterbore generates sufficient heat in said reduced thickness wall and the region of said tube plate surrounding such mating hole in which the tube touches the tube plate as to form a weld therebetween.
Claim 3
Dependent Claim
69 words
The method of welding a tube to a tube plate according to claim 1, wherein said counterboring of the end of the tube is such to such depths that the wall thickness of the tube at its extremity is between one quarter and three quarters of the original wall thickness of the tube and approximates the desired finished contour of the weld to provide a smoothly curved contour thereto.
Claim 4
Dependent Claim
57 words
The method of welding a tube to a tube plate according to claim 1, wherein at least a final counterboring of the end of the tube is performed after positioning of the end of the tube within the hole in the tube plate and the axis of said final counterboring is parallel the axis of said hole.
Claim 5
Independent Claim
168 words
A method of making a heat exchanger, including the steps of welding one end of each of a plurality of tubes in position in a first tube plate; counterboring said opposite ends of said tubes from the other side of said second tube plate to a depth less than the thickness of said second tube plate to define a shoulder of said counterbore within said second tube plate and spaced apart from the face of said second tube plate facing said first tube plate; and welding each thus counterbored end portion in position in the second tube plate in turn by inserting a non-consumable electrode into the counterbored end portion and rotating the electrode around within said counterbored end portion in spaced apart relation thereto while discharging an arc therebetween so that the arc which is produced between the electrode and the adjacent surface of the tube concerned generates intense heat in the region in which the tube touches the second tube plate and forms a weld therebetween.
Claim 6
Independent Claim
168 words
A method of making a heat exchanger, including the steps of welding one end of each of a plurality of tubes in position in a first tube plate; counterboring said opposite ends of said tubes from the other side of said second tube plate to a depth less than the thickness of said second tube plate to define a shoulder of said counterbore within said second tube plate and spaced apart from the face of said second tube plate facing said first tube plate; and welding each thus counterbored end portion in position in the second tube plate in turn by inserting a non-consumable electrode into the counterbored end portion and rotating the electrode around within said counterbored end portion in spaced apart relation thereto while discharging an arc therebetween so that the arc which is produced between the electrode and the adjacent surface of the tube concerned generates intense heat in the region in which the tube touches the second tube plate and forms a weld therebetween.
Claim 7
Dependent Claim
89 words
A method of making a heat exchanger according to claim 4, including the initial steps of counterboring the one end of each tube before it is positioned in a hole in the first tube plate, and positioning that end of the tube in said hole, prior to wElding it in position, a distance greater than the depth of said initial counterboring to ensure the projection into the hole of a part of the end of the tube beyond said initial counterboring and therefore having a relatively greater wall thickness.
Claim 8
Dependent Claim
47 words
A method of making a heat exchanger according to claim 4, including the initial step of partially boring out the other ends of the tubes before they are entered into the respective holes in the second tube plate so that the in situ counterboring required is reduced.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |