US3735478A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods for making bi-metallic pipe
Assignee: Foster Co
•
Filing: 1971-01-06
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Granted: 1973-05-29
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Expires: 1991-01-06
Abstract
Abstract A method for making bi-metallic pipe and a bi-metallic pipe are provided in which a strip of carbon steel having fixed thereto a strip of corrosion resistant metal of the same width is spirally wound into a pipe and welded with a first weldment in the corrosion resistant metal extending into the carbon steel and a second weldment in the carbon steel extending into the first weldment.
Inventors
- 👤 M Porter
- 👤 W Kearns
- 👤 C Washek
- 👤 P Lambert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:19
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/12; B21C37/122; B21C37/123; B23; B23K; B23K9/00; B23K9/02; B23K9/032; B23K9/0325; F; F16; F16L; F16L58/00; F16L58/02; F16L58/04; F16L58/08; F16L9/00; F16L9/16; F16L9/165
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
A method of forming corrosion resistant pipe comprising the steps of: a. forming a strip of carbon steel having fixed thereto a strip of stainless steel of the same width, b. spirally forming a pipe from said strip with the stainless steel forming the inner periphery, c. welding the adjoining spiral edges of the corrosion resistant metal with a first weldment which enters into the carbon steel outer strip and d. welding the adjoining spiral edges of the carbon steel strip with a second weldment which enters the first weldment while remaining wholly within the carbon steel strip.
Claim 2
Independent Claim
98 words
A method of forming corrosion resistant pipe comprising the steps of: a. forming a strip of carbon steel having fixed thereto a strip of stainless steel of the same width, b. spirally forming a pipe from said strip with the stainless steel forming the inner periphery, c. welding the adjoining spiral edges of the corrosion resistant metal with a first weldment which enters into the carbon steel outer strip and d. welding the adjoining spiral edges of the carbon steel strip with a second weldment which enters the first weldment while remaining wholly within the carbon steel strip.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1 wherein the first weldment is a plasma weld.
Claim 4
Dependent Claim
16 words
A method as claimed in claim 1 wherein the first weldment is formed by heli-arc welding.
Claim 5
Dependent Claim
17 words
A method as claimed in claim 2 wherein the second weldment is formed by submerged arc welding.
References Cited (Backward Citations)
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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) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |