Shut-off valve
US5149055A · kind A · utility
8Cited by
7References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1990 |
| Grant date | Sep 22, 1992 |
| Priority date | — |
| Expiry date | Jul 6, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/935
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A piston type of shut-off valve with a sealing ring made of expanded graphite. A plurality of ring-shaped lamellae are each stamped from a foil of expanded graphite and then joined to form a sealing ring. A peripheral edge surface of the sealing ring, rather than its planar facing surface, comes into sealing contact with the piston thereby improving its service life. Service life of the sealing ring can be further improved by using a guard ring on a facing surface of the sealing ring as well as by using an installed density for the sealing ring of 1.5 to 2.2 g/cm.sup.3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.