Valve stem packing structure
US5056758A · kind A · utility
Inventor
Key dates
| Filing date | May 11, 1990 |
| Grant date | Oct 15, 1991 |
| Priority date | — |
| Expiry date | May 11, 2010 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K41/046
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A packing for sealing between a valve stem 31 and valve bonnet 21 which receives the valve stem in a bore 34 formed therein. The packing is accommodated in a packing chamber 41 formed in the valve stem bore 34 which comprises a lower set of packing rings 51 in stacked coaxial relation about the valve stem and a second upper set of packing rings 55 similarly arranged in the upper portion of the packing chamber. A spring means 61, 62, 63 comprising at least one frusto-conical washer is interposed in the packing chamber 41 between the sets of packing rings for axial compression of the upper and lower sets of packing rings to thereby urge the radial expansion of the packing rings and provide an enhanced and substantially uniform sealing effectiveness of the packing rings. A lateral port 68 in the valve bonnet 20 opens between the sets of packing rings and at its outer end is provided with a pressure fitting 70 which may be connected to a leak detecting sensor or alternatively to an external source of injectable sealing substance. A notch in one of said washers allows pressurized sealing material injected through said port to fill the annuluses between the washers and valve stem and bet…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.