US4931235A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making steel/concrete tanks
Assignee: Convault Inc
•
Filing: 1989-03-06
•
Granted: 1990-06-05
•
Expires: 2009-03-06
Abstract
Abstract A method for making a steel/concrete tank is provided. A steel interior tank is pressurized during or after pouring of a concrete outer tank around a steel inner tank. Pressurization is commenced before the concrete has set, and is maintained until substantial setting of the concrete. The resulting structure is less susceptible than previous structures to cracking of the exterior concrete upon pressure-testing of the structure for leaks.
Inventors
- 👤 Thomas A. Lindquist
- 👤 Ralph Bambacigno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:20
CPC Classifications
B; B28; B28B; B28B19/00; B28B19/0038; E; E04; E04G; E04G11/00; E04G11/04; E04G11/045; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49877
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
A method for making a tank encased in concrete, comprising: supporting said tank within a form structure to define a space between the tank and the form structure; pouring a settable concrete in said space; pressuring the interior of said tank to a superambient pressure at least during a time period before said settable concrete has substantially set, so as to expand said tank; substantially maintaining said tank in pressurized state until said settable concrete has set; and reducing said pressure in the interior of said tank to establish a space between said set concrete and said tank.
Claim 2
Independent Claim
98 words
A method for making a tank encased in concrete, comprising: supporting said tank within a form structure to define a space between the tank and the form structure; pouring a settable concrete in said space; pressuring the interior of said tank to a superambient pressure at least during a time period before said settable concrete has substantially set, so as to expand said tank; substantially maintaining said tank in pressurized state until said settable concrete has set; and reducing said pressure in the interior of said tank to establish a space between said set concrete and said tank.
Claim 3
Dependent Claim
18 words
A method, as claimed in claim 1, further comprising enveloping said tank in a sheet of liquid-impervious material.
Claim 4
Dependent Claim
30 words
The method of claim 1, further comprising the step of providing a release material between said tank and the settable concrete to prevent the concrete from adhering to the tank.
Claim 5
Dependent Claim
19 words
A method, as claimed in claim 1, wherein said superambient pressure is at least about 5 lbs./in. 2 .
Claim 6
Dependent Claim
22 words
A method, as claimed in claim 1, further comprising: testing said encased tank by pressurizing said tank at a second superambient pressure.
Claim 7
Independent Claim
127 words
A method for making a tank embedded in concrete, comprising: providing a substantially gas-tight metal tank; enveloping said tank in a sheet of liquid-impervious material; positioning said enveloped tank within a mold to define a space between the tank and the mold; positioning a settable concrete in said space; pressurizing the interior of said tank to a pressure greater than the pressure exterior of the tank at least during a time period before said concrete has set, so the tank expands; substantially maintaining said pressure in the interior of said tank at least until said settable concrete has substantially set; and reducing the pressure in the interior of said tank after the concrete has substantially set to establish a space between said set concrete and said tank.
Claim 8
Independent Claim
127 words
A method for making a tank embedded in concrete, comprising: providing a substantially gas-tight metal tank; enveloping said tank in a sheet of liquid-impervious material; positioning said enveloped tank within a mold to define a space between the tank and the mold; positioning a settable concrete in said space; pressurizing the interior of said tank to a pressure greater than the pressure exterior of the tank at least during a time period before said concrete has set, so the tank expands; substantially maintaining said pressure in the interior of said tank at least until said settable concrete has substantially set; and reducing the pressure in the interior of said tank after the concrete has substantially set to establish a space between said set concrete and said tank.
Claim 9
Independent Claim
72 words
A method for embedding a tank in concrete, comprising: supporting the tank within a form structure to define a space between the tank and the form structure; pouring a settable concrete in said space; pressurizing the interior of said tank at a superambient pressure at least during a time period before said settable concrete has set; and substantially maintaining said superambient pressure in said tank until said settable concrete has substantially set.
Claim 10
Independent Claim
72 words
A method for embedding a tank in concrete, comprising: supporting the tank within a form structure to define a space between the tank and the form structure; pouring a settable concrete in said space; pressurizing the interior of said tank at a superambient pressure at least during a time period before said settable concrete has set; and substantially maintaining said superambient pressure in said tank until said settable concrete has substantially set.
Claim 11
Independent Claim
83 words
A method for embedding a tank in settable concrete, comprising: providing a tank which has buoyancy with respect to said settable concrete; supporting the tank within a form structure to define a space between the tank and the form structure; pouring said settable concrete in said space; filling the tank with a liquid at least to a level sufficient to offset said buoyancy of the tank with respect to said concrete before said concrete has set; and permitting said settable concrete to set.
Claim 12
Independent Claim
83 words
A method for embedding a tank in settable concrete, comprising: providing a tank which has buoyancy with respect to said settable concrete; supporting the tank within a form structure to define a space between the tank and the form structure; pouring said settable concrete in said space; filling the tank with a liquid at least to a level sufficient to offset said buoyancy of the tank with respect to said concrete before said concrete has set; and permitting said settable concrete to set.
References Cited (Backward Citations)
US1555208A
Cited
US1751140A
Cited
US1555209A
Cited
US1958487A
Cited
US1965646A
Cited
US2083491A
Cited
US2777295A
Cited
US3114970A
Cited
US3130520A
Cited
US3151416A
Cited
US3471599A
Cited
US3511692A
Cited
US3562977A
Cited
US4013809A
Cited
US4183221A
Cited
US4273811A
Cited
US4142705A
Cited
US4153103A
Cited
US4372906A
Cited
US4513550A
Cited
US4366654A
Cited
US4387491A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-04 | 1993-12-04 | 1994-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-04 | 1997-12-04 | 1998-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-04 | 2001-12-04 | 2002-06-05 | $7700.00 | Window Closed / Lapsed |