US4624402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for applying an overlay weld for preventing and controlling stress corrosion cracking
Assignee: DUKE ENGINEERING & SERVICES Inc
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Filing: 1983-01-18
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Granted: 1986-11-25
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Expires: 2003-01-18
Abstract
Abstract Stress corrosion cracking 36 at a welded pipe joint 14 in service in a nuclear reactor can be controlled by the location of a overlay weld 18 over the primary weld 16, which extends axially along the pipe on either side of the primary weld 16. The overlay weld 18 is comprised of a plurality of circumferentially and continuously applied weld beads 35, 37 which extend substantially to a minimum distance necessary to produced a favorable residual stress pattern. This distance has been estimated to be the square root of the product of the radius of the pipe times the thickness of the pipe on either side of the primary weld 16.
Inventors
- 👤 David Pitcairn
- 👤 Peter Riccardella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:12
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/02; B23K9/028; B23K9/0282; B23K9/04; B23K9/044; B23K9/046; B23K9/048
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
83 words
A method for controlling and repairing a crack caused by stress corrosion cracking in a heat affected zone on the inner diameter of a welded pipe joint comprising the steps of applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe joint with the crack and extending said overlay weld on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter.
Claim 2
Independent Claim
83 words
A method for controlling and repairing a crack caused by stress corrosion cracking in a heat affected zone on the inner diameter of a welded pipe joint comprising the steps of applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe joint with the crack and extending said overlay weld on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter.
Claim 3
Dependent Claim
49 words
The method of claim 1 including the step of applying an initial weld bead over the pipe joint and then applying a second weld bead adjacent the initial weld bead and a third weld bead adjacent the second weld bead, extending axially from each side of the pipe joint.
Claim 4
Dependent Claim
16 words
The method of claim 1 including the step of simultaneously passing a liquid through the pipe.
Claim 5
Dependent Claim
28 words
The method of claim 1 including the step of applying at least one additional subsequent circumferential and continuous overlay weld on top of the first applied overlay weld.
Claim 6
Independent Claim
105 words
A method for controlling and repairing a crack caused by stress corrosion cracking in the heat affected zone on the inner diameter of a welded pipe joint which is in service as part of a nuclear reactor comprising the steps of applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe with the crack and extending said overlay weld on either side of the pipe joint for a predetermined distance which is about the square root of the product of the radius of the pipe and the thickness of the pipe.
Claim 7
Independent Claim
105 words
A method for controlling and repairing a crack caused by stress corrosion cracking in the heat affected zone on the inner diameter of a welded pipe joint which is in service as part of a nuclear reactor comprising the steps of applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe with the crack and extending said overlay weld on either side of the pipe joint for a predetermined distance which is about the square root of the product of the radius of the pipe and the thickness of the pipe.
Claim 8
Independent Claim
87 words
A method for controlling and repairing a crack caused by stress corrosion cracking in the heat affected zone on the inner diameter of a welded pipe joint comprising the steps of applying a plurality of continuous weld beads transverse to the longitudinal axis of the pipe over the pipe joint with the crack and extending said overlay weld on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter to create a compressive stress effect about the pipe joint.
Claim 9
Independent Claim
87 words
A method for controlling and repairing a crack caused by stress corrosion cracking in the heat affected zone on the inner diameter of a welded pipe joint comprising the steps of applying a plurality of continuous weld beads transverse to the longitudinal axis of the pipe over the pipe joint with the crack and extending said overlay weld on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter to create a compressive stress effect about the pipe joint.
Claim 10
Independent Claim
109 words
A method for controlling and repairing a crack caused by stress corrosion cracking in a heat affected zone on the inner diameter of a welded pipe joint comprising the steps of: applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe joint with the crack; and extending said overlay weld axially on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter for a predetermined distance which is about the square root of the product of the radius of the pipe and the thickness of the pipe.
Claim 11
Independent Claim
109 words
A method for controlling and repairing a crack caused by stress corrosion cracking in a heat affected zone on the inner diameter of a welded pipe joint comprising the steps of: applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe joint with the crack; and extending said overlay weld axially on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter for a predetermined distance which is about the square root of the product of the radius of the pipe and the thickness of the pipe.
Claim 12
Independent Claim
124 words
A method for controlling and repairing a crack caused by stress corrosion cracking in a heat affected zone on the inner diameter of a welded pipe joint comprising the steps of: applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe joint with the crack; calculating the length of a crack; and extending said overlay weld axially on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter for a distance of the length of the crack plus a predetermined distance which is about the square root of the product of the radius of the pipe and the thickness of the pipe.
Claim 13
Independent Claim
124 words
A method for controlling and repairing a crack caused by stress corrosion cracking in a heat affected zone on the inner diameter of a welded pipe joint comprising the steps of: applying to the outer diameter of the pipe an overlay weld including a plurality of circumferentially and continuously applied weld beads over the pipe joint with the crack; calculating the length of a crack; and extending said overlay weld axially on each side of the pipe joint beyond the extremities of the heat affected zone on the inner diameter for a distance of the length of the crack plus a predetermined distance which is about the square root of the product of the radius of the pipe and the thickness of the pipe.
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) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |