Subsurface well safety valve and control system
US4619320A · kind A · utility
64Cited by
7References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1984 |
| Grant date | Oct 28, 1986 |
| Priority date | — |
| Expiry date | Mar 2, 2004 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/04
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Subsurface safety valve assembly (16) for oil wells comprising a valve element (57) and a temperature responsive operator comprising multiple coil springs (69, 70), made of shape memory material, operable in opposing directions for opening and closing the valve element and a ratchet locking mechanism comprising wickers (79) for locking the valve in its open position after removal of the heating which causes shape memory effect movement to such position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.