Valve assembly for the remote control of fluid flow having an automatic time delay
US4270569A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1978 |
| Grant date | Jun 2, 1981 |
| Priority date | — |
| Expiry date | Oct 16, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7853
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A downhole float valve is normally closed by a spring or other means of applying axial pressure until sufficient pressure of drilling fluid from the surface opens the valve. The valve stem includes a dashpot type housing secured thereto and moving within a fluid filled cylinder. When the valve opens, the movement is controlled by a one-way valve in the housing giving a relatively rapid opening. When pressure of the drilling fluid from the surface is removed, the pressure on the underside of the valve typically assisted by the spring, closes the valve. An adjustable bleed passage in the housing delays this closing for a pre-determined time thus allowing the pressure on the underside of the valve to balance with the pressure on the other side of the valve, but preventing an hydraulic lock or an hydraulic "stuck" situation from occurring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.