Coupling units connecting tubular members having a hardened inner wall for carrying mechanically abrasive fluid concrete
US6375228B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1999 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Mar 25, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49879
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A concrete flow line made up of a plurality of end to end pipe sections with pipes connected to each other by a coupling assembly provides for carrying abrasive fluid concrete to a deposit site. The coupling assembly includes an insulating thin sleeve slid over the connecting end of the pipe and spaced from the pipe to form a heat insulating air space therebetween. The thin sleeve is welded to the pipe prior to the hardening of the pipe. After the sleeve is welded in place the inner wall of the pipe is hardened using an induction coil for concentrating of the heat within the inner wall portion in combination with a quenching unit to affect the desired hardening while maintaining an outer ductile wall portion to which the sleeve has been actually welded. A clamping collar or coupler is welded to the sleeve after hardening and forms a connecting end for receiving of a clamp unit which interconnects the adjacent pipe and pipe sections. An elongated raw material pipe of a length which is a multiple of the pipe section in length is provided. A plurality of sleeves are slid over the pipe in appropriate spaced relation and welded to the raw pipe. The elongated raw pipe is then hardened to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.