Apparatus for sealing a fluid carrying device
US5372352A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1990 |
| Grant date | Dec 13, 1994 |
| Priority date | — |
| Expiry date | Sep 28, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/5762
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A novel sealing arrangement for fluid carrying devices and particularly for plug type valves, such as retractable double block and bleed plug valves. The sealing arrangement of the present invention adds secondary and tertiary seals to the conventional packing gland primary seal along the outer surface of the trunnion of such plug type valves. A unique isolated chamber is formed between the secondary and tertiary seals and because of the elastomeric nature of the secondary and tertiary seals, this isolated chamber is bubble tight and thus resists the gradual accumulation of minute leakage, which might otherwise cause false alarms in prior art leakage sensing equipment. Furthermore, the bubble tight feature of a chamber between isolated elastomeric seals, enables purging this chamber for making accurate observations and measurements of true leakage that might otherwise be an environmental hazard. Still more significantly, the bubble tight aspect of the chamber formed between the secondary and tertiary seals of the present invention, provides a means for providing an over-pressure in the chamber by using an inert fluid, such as nitrogen gas, which significantly increases the sealing …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.