Patent ID: 6138989
Filing Date: 2000-10-31
Classification: F16K

Abstract:
A process of providing a new valve seal for butterfly valves for pressures between 150 psi and 600 psi comprising the steps of:providing a butterfly valve having a valve housing with a seat, the seat being oriented with respect to the valve housing to surround a passage within the valve housing, the passage permitting fluid flow through the butterfly valve and the seat;providing a valve disc pivotally moving across the valve housing with respect to the seat from an open position wherein the valve disc is parallel to the fluid flow through the valve housing to a closed position wherein the valve disc is normal to the fluid flow and obstructs fluid flow through registry at a valve seal edge to a seat,providing the valve seal edge with an elastic edge for forming the new valve seal, the elastic edge tapering from a relatively broad cross-section adjacent the valve seal edge to a narrow cross-section away from the valve seal edge;providing an annulus on the valve disc to prevent elastic extrusion of the elastic edge away from the valve seal edge of the valve disc;providing a clamp overlying the valve seal edge beyond the annulus of the valve disc for compressing and extruding the elastic edge, the clamp necking from a relatively broad cross-section adjacent a medial portion of the elastic edge to a narrow cross-section adjacent a periphery of the valve seal edge of the valve disc; and,compressing and extruding the clamp over the elastic edge to cause elastic compression and extrusion of the elastic edge toward the valve seat whereby a compressed and, extruded portion of the narrow cross-section of the elastic edge protrudes from the valve disc edge into contact with the seat to provide the new valve seal.