Replacement main having nozzle and vanes
US5282494A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1992 |
| Grant date | Feb 1, 1994 |
| Priority date | — |
| Expiry date | Aug 31, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16L55/1608
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method is provided for replacing a length of a branch gas main 1 joined to a spine main 2 with a length of replacement main 7 having an outer diameter smaller than the inner diameter of the branch main. In the method access is gained to the bore of the branch main and one end of the replacement main 7 is fed along the branch main 1 via the access point and towards the spine main 2 until the branch main 1 has been replaced. During and after the feeding step gas is prevented from entering any clearance 20 between the mains 1 and 7 by means of a head 9 attached to the leading end of the main 7. After the feeding step a sealant 25 is injected into the branch main 1 to form a seal within the clearance 20.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.