Patent US3857773A successfully refreshed from Google Patents.
US3857773A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suppression of crevice corrosion in gasketed titanium crevices by the use of rubber compound gaskets substantially free of calcium
Assignee: PPG Industries Inc
•
Filing: 1973-04-05
•
Granted: 1974-12-31
•
Expires: 1993-04-05
Abstract
Abstract Disclosed herein is a method of reducing crevice corrosion in titanium structures having gasketed joints, by the use of rubber gaskets characterized by the substantial absence of calcium. Also disclosed is a method of electrolysis in a titanium vessel having gasketed titanium joints with rubber gaskets substantially free of calcium in the joints and crevices.
Inventors
- 👤 Bois D Du
- 👤 W Darlington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:41
CPC Classifications
C; C25; C25B; C25B9/00; F; F16; F16J; F16J15/00; F16J15/02; F16J15/06; F16J15/10; F16J15/102
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
72 words
A METHOD OF PREVENTING CERVICE CORROSION WHICH IS ENCOUNTERED BETWEEN A PAIR OF CLOSELY SPACED SURFACES DURING ELCTROLYSIS UNDER ACIDIC CONDITIONS IN AN ELECTROLYTIC CELL WHEREIN AT LEAST ONE OF SAID SURFACES IS TITANIUM WHICH METHOD COMPRISES PROVIDING A RUBBER GASKET BETWEEN SAID SURFACES IN CONTACT WITH THE TITANIUM WHICH RUBBER GASKET CONTAINS LESS THAN 0.07 WEIGHT PERCENT CALCIUM, DETERMINED BY ATOMIC ABSORPTION SPECTROSCOPY, WHEREBY SAID GASKET IS SUBSTANTIALLY FREE OF CALCIUM.
Claim 2
Independent Claim
72 words
A METHOD OF PREVENTING CERVICE CORROSION WHICH IS ENCOUNTERED BETWEEN A PAIR OF CLOSELY SPACED SURFACES DURING ELCTROLYSIS UNDER ACIDIC CONDITIONS IN AN ELECTROLYTIC CELL WHEREIN AT LEAST ONE OF SAID SURFACES IS TITANIUM WHICH METHOD COMPRISES PROVIDING A RUBBER GASKET BETWEEN SAID SURFACES IN CONTACT WITH THE TITANIUM WHICH RUBBER GASKET CONTAINS LESS THAN 0.07 WEIGHT PERCENT CALCIUM, DETERMINED BY ATOMIC ABSORPTION SPECTROSCOPY, WHEREBY SAID GASKET IS SUBSTANTIALLY FREE OF CALCIUM.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the rubber is chosen from the group consisting of ethylene-propylene-diene rubber, neoprene rubber, and isoprene rubber.
Claim 4
Dependent Claim
29 words
The method of claim 1 wherein said rubber compound contains a filler chosen from the group consisting of carbon black, silica fibers, amorphous silica, sodium silicate, and magnesium silicate.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein said rubber compound contains less than 10 percent calcium in the ash determined by emission spectroscopy.
Claim 6
Dependent Claim
71 words
In an electrolytic cell having an anode and a cathode in a vessel, wherein said vessel comprises at least one titanium member separated from another member by a gasket with a crevice therebetween subject to crevice corrosion, the improvement wherein said gasket in contact with said titanium comprises a rubber compound containing less than 0.07 weight percent calcium, determined by atomic absorption spectroscopy, where said gasket is substantially free of calcium.
Claim 7
Dependent Claim
71 words
In an electrolytic cell having an anode and a cathode in a vessel, wherein said vessel comprises at least one titanium member separated from another member by a gasket with a crevice therebetween subject to crevice corrosion, the improvement wherein said gasket in contact with said titanium comprises a rubber compound containing less than 0.07 weight percent calcium, determined by atomic absorption spectroscopy, where said gasket is substantially free of calcium.
Claim 8
Dependent Claim
21 words
The electrolytic cell of claim 5 wherein the rubber is chosen from the group consisting of ethylene-propylene-diene rubber, and neoprene rubber.
Claim 9
Dependent Claim
30 words
The electrolytic cell of claim 5 wherein said rubber compound comprises a filler chosen from the group consisting of carbon black, silica fibers, amorphous silica, sodium silicate, and magnesium silicate.
Claim 10
Dependent Claim
24 words
The electrolytic cell of claim 5 wherein said rubber compound comprises less than 10 weight percent calcium in the ash determined by emission spectroscopy.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |