Piston actuated well safety valve
US4252197A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 5, 1979 |
| Grant date | Feb 24, 1981 |
| Priority date | — |
| Expiry date | Apr 5, 1999 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/05
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In a well safety valve for controlling the fluid flow through a well conduit in which the valve has a housing and a tubular member controlling a valve element the improvement in means for opening and closing the valve. At least one piston is telescopically movable within and has its longitudinal axis within the wall of the housing and outside of the tubular member and engages the tubular member. The first side of the piston is in communication with a hydraulic passageway adapted to extend to the well surface for opening the valve. The second side of the piston extends into a closed gas chamber tending to move the valve to the closed position. The piston has a small cross-sectional area for reducing the pressure effect in the gas chamber of the gas caused by movement of the second side of the piston whereby the differential between the opening and closing forces are reduced thereby allowing the valve to be used at greater depths in the well. Preferably, valve means is positioned in the piston for charging the gas chamber. In one embodiment the gas chamber and the hydraulic passageway are positioned out of communication with the tubular member thereby eliminating the need for seals o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.