US3688801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for replacing gas mains
Assignee: Individual
•
Filing: 1971-03-09
•
Granted: 1972-09-05
•
Expires: 1991-03-09
Abstract
Abstract Disclosed is a method for economically and quickly replacing sections of deteriorated gas mains by isolating the section to be replaced, inserting in it a replacement section of smaller diameter which carries inflatable bag sealing means bracketing each service line connection to the deteriorated gas main section and which has a normally open, latched closed valve providing communication between the interior of the replacement section and the annular space between the old and replacement main sections and between the bracketing sealing bags. Gas may then be supplied to the replacement section and will reach the service line through the normally open valve and the annular space bracketed by the inflatable bag sealing means. Thus, unless the service line must also be replaced, no direct connection of the service line to the replacement section need be made.
Inventors
- 👤 Carl H Rohrer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:00
CPC Classifications
F; F16; F16L; F16L55/00; F16L55/16; F16L55/162; F16L55/165; F16L55/1657
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
138 words
A method for replacing deteriorated sub-surface gas mains of the type having service lines connected at spaced locations along the gas main, said method including: initially excavating at each end of a predetermined length section of the main and isolating said section from the remainder of the gas main, then inserting within said main section a generally coextensive section of smaller-diameter replacement tube having disposed on its exterior surface inflatable sealing means bracketing at least one of the service line to gas main junctions and a normally open valve providing communication between the interior of said tube section and said junction, subsequently inflating said inflatable sealing means to isolate each service line to gas main junctional area, and finally connecting said tube section to a source of pressurized gas supply to establish gas pressure in said service line.
Claim 2
Independent Claim
138 words
A method for replacing deteriorated sub-surface gas mains of the type having service lines connected at spaced locations along the gas main, said method including: initially excavating at each end of a predetermined length section of the main and isolating said section from the remainder of the gas main, then inserting within said main section a generally coextensive section of smaller-diameter replacement tube having disposed on its exterior surface inflatable sealing means bracketing at least one of the service line to gas main junctions and a normally open valve providing communication between the interior of said tube section and said junction, subsequently inflating said inflatable sealing means to isolate each service line to gas main junctional area, and finally connecting said tube section to a source of pressurized gas supply to establish gas pressure in said service line.
Claim 3
Dependent Claim
96 words
The method claimed in claim 1 but modified by said normally-open valve being latched closed by application of a predetermined pressure to its downstream side and said method having the additional steps: applying pressure at the meter end of said service line to latch closed said normally open valve, then exposing and removing the portions of said gas main section and of said service line at their common junction, and subsequently inserting a replacement length of service line through the original service line and connecting said replacement length of service line to said replacement tube section.
Claim 4
Dependent Claim
52 words
The method claimed in claim 1 in which said inflatable sealing means on said replacement tube section takes the form of inflatable bags and which are inflated by introducing into them a fluid which subsequently solidifies sufficiently to provide a permanent durable seal around each service line to gas main junctional area.
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) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |