Valve for subterranean wells
US4475599A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 1, 1981 |
| Grant date | Oct 9, 1984 |
| Priority date | — |
| Expiry date | May 1, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86976
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The invention relates to an improved subterranean well safety valve wherein an annular actuator is moved downwardly by applied fluid pressure to effect the opening movement of a valve head of a valve relative to an annular valve seat. The initial downward movement of the actuator effects the displacement of a valve stem which extends through a restricted aperture in the valve head, moving a ball valve segment on the valve stem from a seat in the aperture, thus permitting the bleeding of any fluid pressure differential existing on the lower side of the valve head relative to the upper side and reducing the amount of force required to move the valve to its open position. Additionally, in one embodiment, a locking sleeve is slidably mounted within the shiftable annular actuator and such sleeve is operable by an auxiliary tool to effect the radial shifting of locking elements carried by the actuator into locking engagement with the valve housing to achieve a temporary locking of the valve in an open position. The travel of the locking sleeve relative to the valve housing in a reverse direction is limited by a shearable pin so that reverse forcible movement of the locking sleeve will sh…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.