Remotely operable safety valve
US4576358A · kind A · utility
13Cited by
11References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1983 |
| Grant date | Mar 18, 1986 |
| Priority date | — |
| Expiry date | Apr 20, 2003 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/106
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An improved remotely operable safety valve which is adapted for use between the swivel and the kelly is disclosed. An annular hydraulic piston moves the valve to the open and closed position whether or not the drill string is rotating, and in the event of hydraulic failure, the valve may be operated manually. Centering spring means are provided to reduce wear on the operable elements when the valve is in the open position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.