US4218256A
Expired / Lapsed
US
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Method of forming slide gate valve parts
Assignee: NATIONAL REFRACTORIES & MINERALS Corp A CORP OF
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Filing: 1979-03-06
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Granted: 1980-08-19
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Expires: 1999-03-06
Abstract
Abstract Upper and lower plates, as well as other parts, for a slide gate valve are formed by casting into a mold, preferably a metal mold, a castable refractory composition containing from 1 to 5% of a long chain glassy polyphosphate, preferably one having an average chain length of about 20 phosphorous atoms, from 0.1 to 0.5% boric acid, the balance of the castable being sized periclase refractory grain.
Inventors
- 👤 Ralph B. Videtto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:33
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/03; C04B35/04; C04B35/043; B; B22; B22D; B22D41/00; B22D41/14; B22D41/22; B22D41/28; B22D41/30; B22D41/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
74 words
Method of forming a slide gate valve part by casting an admixture of water and a castable refractory into a form wherein the castable refractory consists essentially of (a) from 1 to 5% of a long chain glassy polyphosphate and (b) from 0.1 to 0.5% boric acid, the balance of the castable refractory being sized periclase refractory grain, all percentages being by weight based on the total weight of grain, polyphosphate, and boric acid.
Claim 2
Dependent Claim
74 words
Method of forming a slide gate valve part by casting an admixture of water and a castable refractory into a form wherein the castable refractory consists essentially of (a) from 1 to 5% of a long chain glassy polyphosphate and (b) from 0.1 to 0.5% boric acid, the balance of the castable refractory being sized periclase refractory grain, all percentages being by weight based on the total weight of grain, polyphosphate, and boric acid.
Claim 3
Dependent Claim
14 words
Method according to claim 1 wherein the periclase grain contains at least 90% MgO.
Claim 4
Dependent Claim
14 words
Method according to claim 2 wherein the periclase grain contains at least 95% MgO.
Claim 5
Dependent Claim
27 words
Method according to claim 3 wherein the periclase grain contains about 96.5% MgO and at least 2% CaO and has a lime:silica ratio of at least 2.
Claim 6
Dependent Claim
20 words
Method according to claim 1 wherein the long chain polyphosphate has an average chain length of about 20 phosphorous atoms.
Claim 7
Dependent Claim
20 words
Method according to claim 4 wherein the long chain polyphosphate has an average chain length of about 20 phosphorous atoms.
Claim 8
Dependent Claim
14 words
Method according to claim 6 wherein the castable refractory contains about 0.2% boric acid.
Claim 9
Dependent Claim
15 words
Method according to claim 1 wherein the refractory castable is cast into a metal form.
Claim 10
Dependent Claim
42 words
Method according to claim 1, 2, 3, 4, 5, 6, 7 or 8 wherein the refractory castable, prior to casting, is admixed with from 5 to 8 weight percent water, based on the total weight of refractory grain, polyphosphate, and boric acid.
Claim 11
Dependent Claim
11 words
Method according to claim 9 wherein about 6% water is used.
References Cited (Backward Citations)
US3960580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-19 | 1984-02-18 | 1984-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-19 | 1988-02-18 | 1988-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-19 | 1992-02-18 | 1992-08-19 | $7700.00 | Window Closed / Lapsed |