US4016394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of longitudinally welded pipe
Assignee: KM Kabelmetal AG
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Filing: 1975-02-10
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Granted: 1977-04-05
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Expires: 1995-02-10
Abstract
Abstract In the production of longitudinally welded pipes, the metal strip is treated with a chemical deoxidizing agent, such as a hydrazine compound, to remove oxides from at least the strip edges, prior to arc welding, to provide an improved weld.
Inventors
- 👤 Meinhard Hecht
- 👤 Herbert Kubiak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:27
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/02; B23K9/025; B23K9/0253
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
67 words
A process for producing longitudinally welded pipe from a metal strip wherein the metal is selected from the group consisting of copper and its alloys, comprising: cleaning oxide from at least the edges of the metal strip with a hydrazine compound; washing the strip to remove remaining hydrazine compound; forming the strip into a pipe; are arc welding the formed pipe to produce the longitudinally welded pipe.
Claim 2
Dependent Claim
67 words
A process for producing longitudinally welded pipe from a metal strip wherein the metal is selected from the group consisting of copper and its alloys, comprising: cleaning oxide from at least the edges of the metal strip with a hydrazine compound; washing the strip to remove remaining hydrazine compound; forming the strip into a pipe; are arc welding the formed pipe to produce the longitudinally welded pipe.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the strip is degreased prior to cleaning oxide therefrom.
Claim 4
Dependent Claim
15 words
The process of claim 2 wherein at least the strip edge portions are mechanically cleaned.
Claim 5
Dependent Claim
22 words
The process of claim 3 wherein the strip edges are mechanically cleaned by brushing while cleaning the oxide with the hydrazine compound.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein the longitudinally welded pipe has a wall thickness of less than 0.2 mm.
Claim 7
Dependent Claim
14 words
The process of claim 5 wherein the longitudinally welded pipe is a copper pipe.
Claim 8
Dependent Claim
13 words
The process of claim 6 wherein the hydrazine compound is a hydrazine salt.
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) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |