US3900939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of plugging steam generator tubes
Assignee: Combustion Engineering Inc
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Filing: 1973-10-31
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Granted: 1975-08-26
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Expires: 1993-10-31
Abstract
Abstract A method for plugging the ends of defective tubes in shell and tube heat exchangers is described. The plug utilized in the method is fabricated from a metallic alloy having a mechanical memory characteristic whereby it can be physically deformed into a reduced diameter for insertion into the tube end and thereafter induced to assume its original diameter to thus secure the plug within the tube.
Inventors
- 👤 John Stuart Greacen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:17
CPC Classifications
F; F28; F28F; F28F11/00; F28F11/02; B; B21; B21D; B21D39/00; B21D39/06; B23; B23P; B23P11/00; B23P11/02; B23P11/025; C; C08; C08L; C08L2201/00; C08L2201/12; F28F2255/00; F28F2255/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49352; Y10T29/49718; Y10T29/49732; Y10T29/49826; Y10T29/49863; Y10T29/49865; Y10T403/00; Y10T403/48
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
166 words
A method of retaining a hollow cylindrical body within the interior of a tube comprising the steps of: a. forming a hollow, cylindrical body of a material containing about 53 percent to 57 percent nickel and the balance being predominantly titanium and having an external diameter greater than the internal diameter of the tube to receive the same; b. heating said body to a temperature of about 900*F while restraining the same to prevent expansion of its physical dimensions; c. cooling said body to a temperature below the minimum limit of the transition range of temperatures for said material; d. reducing the external diameter of said cooled body by a cold deforming operation for a clearance fit with respect to the internal diameter of said tube; e. inserting said cooled body in said tube; and f. heating said body to a temperature above the maximum limit of said transition range of temperatures for said material to cause expansion of said body into engagement with said tube.
Claim 2
Independent Claim
166 words
A method of retaining a hollow cylindrical body within the interior of a tube comprising the steps of: a. forming a hollow, cylindrical body of a material containing about 53 percent to 57 percent nickel and the balance being predominantly titanium and having an external diameter greater than the internal diameter of the tube to receive the same; b. heating said body to a temperature of about 900*F while restraining the same to prevent expansion of its physical dimensions; c. cooling said body to a temperature below the minimum limit of the transition range of temperatures for said material; d. reducing the external diameter of said cooled body by a cold deforming operation for a clearance fit with respect to the internal diameter of said tube; e. inserting said cooled body in said tube; and f. heating said body to a temperature above the maximum limit of said transition range of temperatures for said material to cause expansion of said body into engagement with said tube.
Claim 3
Independent Claim
157 words
A method of plugging the end of a tube comprising the steps of: a. forming a cylindrical plug containing from about 53 to 57 percent nickel and the balance being predominantly titanium and having an external diameter greater than the internal diameter of the tube to be plugged; b. heating said plug to a temperature of about 900*F while restrAining the same to prevent expansion of its physical dimensions; c. cooling said plug to a temperature below the minimum limit of the transition range of temperatures for the plug material; d. reducing the external diameter of said cooled plug by a cold deforming operation for a clearance fit with respect to said tube to be plugged; e. inserting said cooled plug in said tube; and f. heating said plug to a temperature above the maximum limit of said transition range of temperatures for the plug material to cause expansion of said plug into engagement with said tube.
Claim 4
Independent Claim
157 words
A method of plugging the end of a tube comprising the steps of: a. forming a cylindrical plug containing from about 53 to 57 percent nickel and the balance being predominantly titanium and having an external diameter greater than the internal diameter of the tube to be plugged; b. heating said plug to a temperature of about 900*F while restrAining the same to prevent expansion of its physical dimensions; c. cooling said plug to a temperature below the minimum limit of the transition range of temperatures for the plug material; d. reducing the external diameter of said cooled plug by a cold deforming operation for a clearance fit with respect to said tube to be plugged; e. inserting said cooled plug in said tube; and f. heating said plug to a temperature above the maximum limit of said transition range of temperatures for the plug material to cause expansion of said plug into engagement with said tube.
Claim 5
Dependent Claim
24 words
The method recited in claim 2 in which said plug is slow cooled to ambient temperature following the step of heating up to 900*F.
Claim 6
Dependent Claim
25 words
The method recited in claim 3 in which said plug is cooled to a temperature below about 0*F prior to performing said cold deforming operation.
Claim 7
Dependent Claim
23 words
The method recited in claim 3 in which said cold deforming operation comprises swaging the exterior of said plug to a reduced diameter.
References Cited (Backward Citations)
US2647847A
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US3555656A
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US3579805A
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US3590877A
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US3558369A
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US3805567A
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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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |