US3668360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic pipeline welding method
Assignee: Individual
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Filing: 1971-02-24
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Granted: 1972-06-06
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Expires: 1991-02-24
Abstract
Abstract The method for automatically welding pipelines by means of a gas shielded short circuiting electric arc is disclosed wherein the arc is supplied by a consumable metal electrode which is connected in parallel to both a constant voltage power source and a constant current power source. A solid non-consumable metal backup plate is positioned against the root opening of the weld joint, an arc is established between the electrode and the pipeline and the electrode is moved along the circumference of the pipeline in proximity to the weld joint. The electrode is supplied to the joint at a constant feed rate selected from the range of between 350 and 1,000 inches per minute during each of a stringer bead pass, one or more filler passes, and a cap pass of the electrode about the circumference of the pipeline. During each of the passes the current supplied to the electrode by the constant current source is selected in accordance with the feed rate in order to maintain the current supplied by the constant voltage source, and thus the arc force, below a predetermined level for each selected feed rate while maintaining a short circuiting type welding operation.
Inventors
- 👤 William L Ballis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:06
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/02; B23K9/028; B23K9/0282; B23K9/0286
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
335 words
The method of automatically welding a circumferential weld joint between the edges of a pair of pipes positioned end to end in the pipeline by means of an electric arc supplied by a consumable metal electrode comprising the steps of, positioning a solid metal backup plate across the root opening of said weld joint, electrically connecting said metal electrode in parallel to a constant voltage power source and a constant current power source, selecting the voltage output of said constant voltage power source at a level within the range of 19 to 25 volts; initially supplying said electrode to said joint at a constant feed rate selected from the range of 500 to 900 inches per minute, establishing a short circuiting electric arc between said electrode and said pipeline, moving said consumable electrode in a stringer pass along the circumference of said pipeline in proximity to said weld joint, selecting the current level supplied to said electrode by said constant current source during said stringer pass in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 160 amperes; upon completion of said stringer pass, supplying said electrode to said joint a constant feed rate selected from the range of 600 to 1,000 inches per minute, moving said consumable electrode in a filler pass along the circumference of said pipeline in proximity to said weld joint, selecting the current level supplied to said electrode by said constant current source during said filler pass in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 200 amperes; maintaining the distance between the electrical contact tip of said electrode and said backup at a distance within the range of five-eighths to three-fourths of an inch during said stringer and filler passes, and moving said electrode along the circumference of said pipeline during said passes at a rate of between 10 and 35 inches per minute.
Claim 2
Independent Claim
335 words
The method of automatically welding a circumferential weld joint between the edges of a pair of pipes positioned end to end in the pipeline by means of an electric arc supplied by a consumable metal electrode comprising the steps of, positioning a solid metal backup plate across the root opening of said weld joint, electrically connecting said metal electrode in parallel to a constant voltage power source and a constant current power source, selecting the voltage output of said constant voltage power source at a level within the range of 19 to 25 volts; initially supplying said electrode to said joint at a constant feed rate selected from the range of 500 to 900 inches per minute, establishing a short circuiting electric arc between said electrode and said pipeline, moving said consumable electrode in a stringer pass along the circumference of said pipeline in proximity to said weld joint, selecting the current level supplied to said electrode by said constant current source during said stringer pass in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 160 amperes; upon completion of said stringer pass, supplying said electrode to said joint a constant feed rate selected from the range of 600 to 1,000 inches per minute, moving said consumable electrode in a filler pass along the circumference of said pipeline in proximity to said weld joint, selecting the current level supplied to said electrode by said constant current source during said filler pass in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 200 amperes; maintaining the distance between the electrical contact tip of said electrode and said backup at a distance within the range of five-eighths to three-fourths of an inch during said stringer and filler passes, and moving said electrode along the circumference of said pipeline during said passes at a rate of between 10 and 35 inches per minute.
Claim 3
Dependent Claim
37 words
The method of claim 1 wherein said step of positioning a solid metal backup plate across said root opening includes the step of engaging said plate with at least one of said pipes adjacent the edge thereof.
Claim 4
Dependent Claim
30 words
The method of claim 2 including the step of oscillating said electrode across said joint during said filler pass at the rate of between one and four cycles per second.
Claim 5
Dependent Claim
22 words
The method of claim 1 including the step of shielding the welding arc with a gas mixture of argon and carbon dioxide.
Claim 6
Independent Claim
214 words
The method of automatically welding the stringer bead pass of a circumferential weld joint between the edges of a pair positioned end to end in a pipeline by means of an electric arc supplied by a consumable metal electrode comprising the steps of, electrically connecting said metal electrode in parallel to a constant voltage power source and a constant current power source, positioning a solid metal backup plate across the root opening of said weld joint, supplying said electrode to said joint at a constant feed rate selected from the range of 500 to 900 inches per minute, selecting the current level supplied to said electrode by said constant current source in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 160 amperes, selecting the distance between the electrical contact tip of said electrode and said backup at a distance within the range of five-eighths to three-fourths of an inch, establishing a short circuiting electric arc between said electrode and said pipeline, moving said electrode along the circumference of said pipeline in proximity to said weld joint at a rate of between 10 and 35 inches per minute, and shielding the welding arc with a gas mixture of argon and carbon dioxide.
Claim 7
Independent Claim
214 words
The method of automatically welding the stringer bead pass of a circumferential weld joint between the edges of a pair positioned end to end in a pipeline by means of an electric arc supplied by a consumable metal electrode comprising the steps of, electrically connecting said metal electrode in parallel to a constant voltage power source and a constant current power source, positioning a solid metal backup plate across the root opening of said weld joint, supplying said electrode to said joint at a constant feed rate selected from the range of 500 to 900 inches per minute, selecting the current level supplied to said electrode by said constant current source in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 160 amperes, selecting the distance between the electrical contact tip of said electrode and said backup at a distance within the range of five-eighths to three-fourths of an inch, establishing a short circuiting electric arc between said electrode and said pipeline, moving said electrode along the circumference of said pipeline in proximity to said weld joint at a rate of between 10 and 35 inches per minute, and shielding the welding arc with a gas mixture of argon and carbon dioxide.
Claim 8
Dependent Claim
37 words
The method of claim 5 wherein said step of positioning a solid metal backup plate across said root opening includes the step of engaging said plate with at least one of said pipes adjacent the edge thereof.
Claim 9
Dependent Claim
22 words
The method of claim 6 including the step of establishing the voltage supplied by said constant power source at approximately 24 volts.
Claim 10
Independent Claim
217 words
The method of automatically welding the filler pass of a circumferential weld joint between the edges of a pair of pipes positioned end to end in a pipeline by means of an electric arc supplied by a consumable metal electrode comprising the steps of electrically connecting said metal electrode in parallel to a constant voltage power source and a constant current power source, positioning a solid metal backup plate across the root opening of said weld joint, supplying said electrode to said joint at a constant feed ratE selected from within the range of 600 to 1,000 inches per minute, selecting the current level supplied to said electrode by said constant current source in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 200 amperes, selecting the distance between the electrical contact tip of said electrode and the backup plate at a distance within the range of five-eighths to three-fourths of an inch, establishing a short circuiting electric arc between said electrode and said pipeline, moving said electrode along the circumference of said pipeline in proximity to said weld joint at a rate of between 10 and 35 inches per minute, and shielding the welding arc with a gas mixture of argon and carbon dioxide.
Claim 11
Independent Claim
217 words
The method of automatically welding the filler pass of a circumferential weld joint between the edges of a pair of pipes positioned end to end in a pipeline by means of an electric arc supplied by a consumable metal electrode comprising the steps of electrically connecting said metal electrode in parallel to a constant voltage power source and a constant current power source, positioning a solid metal backup plate across the root opening of said weld joint, supplying said electrode to said joint at a constant feed ratE selected from within the range of 600 to 1,000 inches per minute, selecting the current level supplied to said electrode by said constant current source in accordance with the selected electrode feed rate to maintain the current level supplied by said constant voltage source to at most 200 amperes, selecting the distance between the electrical contact tip of said electrode and the backup plate at a distance within the range of five-eighths to three-fourths of an inch, establishing a short circuiting electric arc between said electrode and said pipeline, moving said electrode along the circumference of said pipeline in proximity to said weld joint at a rate of between 10 and 35 inches per minute, and shielding the welding arc with a gas mixture of argon and carbon dioxide.
Claim 12
Dependent Claim
24 words
The method of claim 8 wherein said step of oscillating said electrode across said joint at the rate of approximately four cycles per second.
Claim 13
Dependent Claim
22 words
The method of claim 9 including the step of establishing the voltage supplied by said constant power source at approximately 24 volts.
Claim 14
Dependent Claim
32 words
The method of claim 10 including the step of selecting the speed of movement of said electrode along the circumference of said pipeline at a rate of approximately 35 inches per minute.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |