Patent US3805459A successfully refreshed from Google Patents.
US3805459A
Expired / Lapsed
US
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Method of reducing notch sensitivity in tubular products
Assignee: Zirconium Technology Corp
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Filing: 1972-01-17
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Granted: 1974-04-23
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Expires: 1992-01-17
Abstract
Abstract A method of reducing notch sensitivity in tubular products, to inhibit premature bursting on such being subjected to a high internal pressure. An interior circumferential region is uniformly roughened in the product together with removal of some material in the wall of the product. Such effectively eliminates notches as stress risers, and on a high internal pressure condition occurring, resultant stress is distributed throughout the uniformly roughened region.
Inventors
- 👤 I Baksay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:39
CPC Classifications
B; B24; B24C; B24C1/00; B24C1/10; C; C21; C21D; C21D7/00; C21D7/02; C21D7/04; C21D7/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
143 words
A method of processing a tubular product to inhibit bursting of the product on its being subjected to a high internal pressure condition, the method comprising preparing the tubular product with a relatively smooth internal circumferential region with any surface discontinuities therein having a penetration into the wall of the product limited to less than about 2 mils, blasting with particles of abrasive the internal circumferential region of the tubular product to obtain over such region a surface roughness within the range of about 20 to 50 RMS, and with such blasting removing material to reduce average wall thickness at least about one third of the indicated limit of surface penetration, the method producing a product operable, with a high internal pressure condition occurring which stresses the product, to produce distribution of stress throughout the uniformly roughened internal circumferential region of the product.
Claim 2
Independent Claim
143 words
A method of processing a tubular product to inhibit bursting of the product on its being subjected to a high internal pressure condition, the method comprising preparing the tubular product with a relatively smooth internal circumferential region with any surface discontinuities therein having a penetration into the wall of the product limited to less than about 2 mils, blasting with particles of abrasive the internal circumferential region of the tubular product to obtain over such region a surface roughness within the range of about 20 to 50 RMS, and with such blasting removing material to reduce average wall thickness at least about one third of the indicated limit of surface penetration, the method producing a product operable, with a high internal pressure condition occurring which stresses the product, to produce distribution of stress throughout the uniformly roughened internal circumferential region of the product.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein the blasting is performed from opposite ends of the tubular product tO obtain a substantially uniform reduction in wall thickness throughout the entire length of the product.
Claim 4
Dependent Claim
27 words
The method of claim 1 which further comprises the step of pickling the internal circumferential region of the tubular product performed after blasting with particles of abrasive.
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) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |