Ball valve having convex seat
US6293517A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Feb 28, 2000 |
| Grant date | Sep 25, 2001 |
| Priority date | — |
| Expiry date | Feb 28, 2020 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/04
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A valve includes a valve ball and a convex metal valve seat ring that abut along a circle in a metal-to-metal seal. At very high contact forces, the valve ball and/or the valve seat elastically deform to increase the contact area between them and thereby lower the contact pressures applied to the valve ball and valve seat. The valve ball and valve seat are made of materials that do not pressure weld under a wide range of contact pressures. In one embodiment, the valve ball is a stainless steel alloy having a hardness of at least Rockwell 44C and the valve seat is Stellite having a hardness of at least Rockwell 50C. In another embodiment, the valve ball and seat ring are steel alloys having hardnesses above Rockwell 50C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.