Fail-safe blowout preventer
US4877217A · kind A · utility
29Cited by
2References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1988 |
| Grant date | Oct 31, 1989 |
| Priority date | — |
| Expiry date | Oct 27, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/062
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A fail-safe mechanism for closing the rams in a conventional blowout preventer. The mechanism includes a ram shaft having an enlarged outer end that is exposed to well pressure which exerts a constant closing force. The closing force is opposed by a hydraulic fluid chamber which is evacuated in the event of fire, etc. A floating plug within the ram shaft helps prevent leaks of well fluid from the blowout preventer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.