Safety valve
US3941348A · kind A · utility
67Cited by
7References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 7, 1974 |
| Grant date | Mar 2, 1976 |
| Priority date | — |
| Expiry date | May 7, 1994 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/04
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A remotely operable safety valve mounted between the swivel and the kelly in drilling operation including a spherically-shaped valve element which is mounted in a generally tubular housing rotatable with the swivel sub, the kelly and the drill string. Hydraulic means move the valve element between open and closed positions in order to control flow through the drill-string and prevent in-line blow outs. As an additional safety feature, spring means move the valve element to a closed position in the event of a failure of the hydraulic means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.