Bushing-less stem guided control valve
US5791629A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1996 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Oct 31, 2016 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K41/02
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fluid control valve in which the usual metal stem guide bushings have been eliminated. A fluid control valve includes a valve bonnet and a packing nut threadably engaging the valve bonnet. A valve stem passes through the valve bonnet and the packing nut in a clearance fit so that there is no engagement therebetween. Two packing sets of V-type PTFE packing are included with each set having a middle virgin PTFE sealing ring, a carbon or glass filled PTFE male packing ring on one side and a carbon or glass filled PTFE female ring on the other side. Belleville disk springs are provided intermediate the packing nut and the two packing sets, for supplying live loading to the packing. In an unloaded condition, initially the packing sets both are in a clearance fit with the valve stem. Threadably inserting the packing nut into the valve bonnet until there are no visible threads at the top of the bonnet ensures a sufficient loading to seal the valve stem, seal the inside diameter of the bonnet, and to provide a sufficient stem guidance, interference fit with the valve stem to enable the usual upper and lower metal guide bushings to be eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.