Secondary sealing device
US3947044A · kind A · utility
12Cited by
6References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 7, 1975 |
| Grant date | Mar 30, 1976 |
| Priority date | — |
| Expiry date | Jul 7, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/929
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A secondary sealing device is provided for a pump used for pumping gases under pressure. Leakage of gas between a main seal and the pump shaft is permitted up to a predetermined maximum pressure but once that pressure has been exceeded, a pressure sensor activates a switch to stop rotation of the pump shaft. When the shaft has come to a halt, a high pressure gas such as nitrogen is introduced into a secondary seal circumferential of the shaft whereby a resilient sealing ring is forced into tight sealing contact with the pump shaft to prevent any further leakage of the pumped gas to the atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.