US4071083A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tubular exchanger
Assignee: Creusot Loire SA
•
Filing: 1976-03-18
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Granted: 1978-01-31
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Expires: 1996-03-18
Abstract
Abstract A tubular exchanger for operations under conditions of heat and pressure comprising a set of tubes made of ferritic steel having the following composition: C ≦ 0.010%, Cr 25 to 30%, Mo < 4%. The tubes are provided at each end with relatively short ferrules of austenitic stainless steel which are welded to the tubes.
Inventors
- 👤 Rene Henri Droin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:52
CPC Classifications
F; F28; F28F; F28F9/00; F28F9/02; F28F9/04; F28F9/16; F28F9/18; F28F9/185; B; B23; B23K; B23K35/00; B23K35/001; B23K35/004; F28F21/00; F28F21/08; F28F21/081; F28F21/082; F28F21/083; Y; Y10; Y10S; Y10S165/00; Y10S165/454; Y10S165/492; Y10S165/493; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49391
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
137 words
A tubular exchanger for working under heat and pressure, comprising a set of tubes made of ferritic steel of high chrome content having the following composition: C < 0.010%, cr: 25 to 30%, Mo < 4%, relatively short tubular ferrules of austenitic stainless steel, weld means joining said ferrules respectively to said tubes with a low degree of contamination, said stainless steel of said ferrules having the following composition: C < 0.020%, cr: 20 to 26%, Ni: 6 to 26%, Mo: 1 to 5%, a tube plate receiving said ferrules, said tube plate being clad with an austenitic stainless steel having the following composition: C < 0.030%, cr: 18 to 22%, Ni: 14 to 18%, Mo: 1 to 3%, Mn: 4 to 6%. and second weld means joining said ferrules to said cladding of said tube plate.
Claim 2
Dependent Claim
137 words
A tubular exchanger for working under heat and pressure, comprising a set of tubes made of ferritic steel of high chrome content having the following composition: C < 0.010%, cr: 25 to 30%, Mo < 4%, relatively short tubular ferrules of austenitic stainless steel, weld means joining said ferrules respectively to said tubes with a low degree of contamination, said stainless steel of said ferrules having the following composition: C < 0.020%, cr: 20 to 26%, Ni: 6 to 26%, Mo: 1 to 5%, a tube plate receiving said ferrules, said tube plate being clad with an austenitic stainless steel having the following composition: C < 0.030%, cr: 18 to 22%, Ni: 14 to 18%, Mo: 1 to 3%, Mn: 4 to 6%. and second weld means joining said ferrules to said cladding of said tube plate.
Claim 3
Dependent Claim
25 words
A tubular exchanger as claimed in claim 1, wherein the Cr and Mo content of said steel of said tubes is 26% and 1% respectively.
Claim 4
Dependent Claim
30 words
A tubular exchanger as claimed in claim 1, wherein the Cr, Ni, Mo and Mn content of said steel cladding said tube plates is 20%, 16%, 2% and 5% respectively.
Claim 5
Dependent Claim
19 words
A tubular exchanger as claimed in claim 1 wherein said tube plates are made of carbon or low-alloy steel.
Claim 6
Dependent Claim
25 words
A tubular exchanger as claimed in claim 1 wherein the first weld means is disposed at a location within the thickness of said tube plate.
Claim 7
Dependent Claim
125 words
A tubular exchanger for working under heat and pressure, comprising a set of tubes made of ferritic steel, a ferrule of austenitic stainless steel welded to each end of each tube, and a pair of tube plates clad in austenitic stainless steel, said ferrules being welded to said cladding, and wherein said steel of said tubes has the following composition: C < 0.010%, cr: 25 to 30%, Mo < 4%, said steel of said ferrules has the following composition; C < 0.020%, cr: 20 to 26%, Ni: 6 to 26%, Mo: 1 to 5%, and said steel of said tube plate cladding has the following composition: C ≦ 0.030%, cr: 18 to 22%, Ni: 14 to 18%, Mo: 1 to 3%, Mn: 4 to 6%.
Claim 8
Dependent Claim
125 words
A tubular exchanger for working under heat and pressure, comprising a set of tubes made of ferritic steel, a ferrule of austenitic stainless steel welded to each end of each tube, and a pair of tube plates clad in austenitic stainless steel, said ferrules being welded to said cladding, and wherein said steel of said tubes has the following composition: C < 0.010%, cr: 25 to 30%, Mo < 4%, said steel of said ferrules has the following composition; C < 0.020%, cr: 20 to 26%, Ni: 6 to 26%, Mo: 1 to 5%, and said steel of said tube plate cladding has the following composition: C ≦ 0.030%, cr: 18 to 22%, Ni: 14 to 18%, Mo: 1 to 3%, Mn: 4 to 6%.
Claim 9
Dependent Claim
19 words
A tubular exchanger as claimed in claim 6 wherein said tube plates are made of carbon or low-alloy steel.
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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) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |