Fluid pressure actuator having bias element immersed in non-corrosive environment
US4442757A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 24, 1981 |
| Grant date | Apr 17, 1984 |
| Priority date | — |
| Expiry date | Aug 24, 2001 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01B31/18
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An improved valve actuator is provided for employment in environments such as subterranean wells where highly corrosive gases and fluids are contained in the well fluid which is normally pressurized and employed to operate the actuator. The bias element opposing the pressure induced movements of the piston unit of the actuator is disposed in an isolation chamber defined between two axially spaced, radial shoulders provided on the piston and having sealing engagement with the bore of the cylindrical wall, thus defining constant volume annular chamber that is isolated from the highly corrosive fluids and gases. The isolated chamber moves with the piston and thus does not provide fluid pressure opposition to the fluid pressure induced movement of the piston.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.