Equipment for working on liquid-filled conduits
Abstract
Abstract THE APPARATUS ACCORDING TO THE PRESENT INVENTION PERMITS WORKING ON LIQUID-FILLED PIPES WITHOUT HAVING TO DRAIN THEM. IT COMPRISES AT LEAST ONE SUBSTANTIALLY ANNULAR MEMBER OF ELASTOMERIC MATERIAL WHICH IS PLACED ABOUT A PIPE SECTION AND PROVIDED WITH INNER SEALING LIPS ENGAGING THE PIPE SECTION SO AS TO SPACE THE INNER SURFACE OF THE ANNULAR MEMBER FROM THE OUTER SURFACE OF THE PIPE SECTION AND DEFINE BETWEEN THEM A SEALED SUBSTANTIALLY ANNULAR CLEARANCE. A REFRIGERATING UNIT IS PROVIDED, AND A REFRIGERANT COOLED BY THE REFRIGERATING UNIT IS CIRCULATED THROUGH THIS ANNULAR CLEARANCE TO THEREBY FREEZE THE LIQUID IN THE PIPE SECTION AND TO FORM IN THE LATTER AN ICE PLUG WHICH PREVENTS CIRCULATION OF LIQUID THROUGH THE PIPE AND ENABLES WORK ON THE PIPE DOWNSTREAM OF THE ICE PLUG WITHOUT REQUIRING DRAINING OF THE LIQUID.
Inventors
- 👤 Werner Scheidler
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |