Balanced stem fail-safe valve system
USRE30115E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Jan 19, 1978 |
| Grant date | Oct 16, 1979 |
| Priority date | — |
| Expiry date | Jan 19, 1998 |
Classification
- Technology area (CPC —)General
Abstract
A balanced stem fail-safe valve controls flow of fluids through a submerged pipeline. A closed subsea hydraulic pressure system operates or powers the valve. In the fail-safe mode the operating or reservoir pressure equals ambient sea pressure. A valve housing is arranged on the pipeline and a valve chamber is formed in the valve housing. A valve element is movable in the valve chamber between open and closed positions to control the flow of fluids through the pipeline. A first fluid pressure operable means is connected to the valve element to move the valve element to open position upon application of pump pressure to the first fluid pressure operable means. Electrically operated valves are used to direct the flow of power fluid to and from the valve. A spring is arranged in the valve housing to urge the valve element to its closed position in the event of power failure. A second fluid pressure operable means detached from the valve element engages the valve element upon application of operating or reservoir pressure to the second fluid pressure operable means to balance any unwanted force which might occur when the ambient pressure is greater than the internal valve pressure and …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.