Spiral wound gasket

Abstract

A spiral wound gasket includes a resilient sealing element including spirally wound, alternating layers of metal banding and winding fill material that incorporates a significant quantity of talc with quantities of fiber and binder. Either or both of an outer guide ring and inner guide ring may extend from peripheral outer and inner surfaces of the sealing element. Embodiments of the gasket overlay one or both axial faces of the sealing element with a layer facing material that incorporates a significant quantity of talc with quantities of fiber and binder.

What is claimed is: 
     
         1 . A spiral wound gasket comprising:
 a resilient sealing element including spirally wound, alternating layers of metal banding and winding fill material; the winding fill material comprising talc; and   a layer of facing material adhered to at least one axial face of the sealing element of the spiral wound gasket.   
     
     
         2 . The spiral wound gasket of  claim 1  further comprising:
 an outer guide ring extending radially from an outer periphery of the sealing element. 
 
     
     
         3 . The spiral wound gasket of  claim 2  further comprising:
 an inner guide ring extending radially from an inner periphery of the sealing element. 
 
     
     
         4 . The spiral bound gasket of  claim 1  wherein:
 the winding fill material includes from approximately 60% to 90% by weight talc, approximately 1% to 14% by weight fiber, and approximately 1% to 8% by weight binder 
 
     
     
         5 . The spiral bound gasket of  claim 1  wherein:
 the winding fill material includes greater than 60% by weight talc, less than 20% by weight fiber, and less than 5% by weight organic binder. 
 
     
     
         6 . The spiral bound gasket of  claim 1  wherein:
 the winding fill material is comprised of approximately 90% by weight talc, 7% by weight fiber, and 3% by weight binder. 
 
     
     
         7 . The spiral wound gasket of  claim 1  wherein:
 annular layers of facing material are adhered to opposing axial faces of the spiral wound gasket. 
 
     
     
         8 . The spiral wound gasket of  claim 1  wherein:
 the talc is a low particle size talc having a particle size in the range of from 0.2 microns to 1.5 microns. 
 
     
     
         9 . A spiral wound gasket comprising:
 a resilient sealing element including spirally wound, alternating layers of metal banding and winding fill material; the winding fill material includes greater than 60% by weight talc;   an outer guide ring extending radially from an outer periphery of the sealing element; and   a layer of facing material adhered to at least one axial face of the sealing element of the spiral wound gasket, the facing material includes greater than 60% by weight talc.   
     
     
         10 . The spiral bound gasket of  claim 9  wherein:
 the winding fill material includes from approximately 60% to 90% by weight talc, approximately 1% to 14% by weight fiber, and approximately 1% to 8% by weight binder. 
 
     
     
         11 . The spiral bound gasket of  claim 9  wherein:
 the winding fill material and the layer of facing material both including from approximately 60% to 90% by weight talc, approximately 1% to 14% by weight fiber, and approximately 1% to 8% by weight binder. 
 
     
     
         12 . A spiral wound gasket comprising:
 a resilient sealing element including spirally wound, alternating layers of metal banding; and   a layer of facing material adhered to at least one axial face of the sealing element of the spiral wound gasket;   the layer of facing material including from approximately 60% to 90% by weight talc, approximately 1% to 14% by weight fiber, and approximately 1% to 8% by weight binder.   
     
     
         13 . A method of manufacturing a spiral wound gasket comprising:
 preparing a winding fill material by
 preparing a talc slurry; 
 preparing a sheet slurry comprising the talc slurry; 
 forming a pre-densified gasket sheet from the sheet slurry; and 
 densifying the pre-densified gasket sheet to form winding fill material; and 
   forming a resilient spiral core by winding a metal banding and strips of the winding fill material into a spiral of overlying turns.   
     
     
         14 . The method as recited in  claim 13 , wherein the talc slurry comprises from 10 wt % to 40 wt % talc and from 60 wt % to 90 wt % water. 
     
     
         15 . The method as recited in  claim 13 , wherein preparing the sheet slurry comprises:
 mixing inorganic fiber with water to form a first mixture;   mixing the talc slurry with the first mixture to form a second mixture; and   mixing binder with the second mixture to form the gasket sheet slurry.   
     
     
         16 . The method as recited in  claim 15 , further comprising mixing flocculant and defoamer with the gasket sheet slurry. 
     
     
         17 . The method as recited in  claim 13 , wherein densifying the pre-densified gasket sheet comprises applying heat in the range of from 300 to 400° F. and pressure in the range of from 700 to 800 psi to the pre-densified gasket sheet. 
     
     
         18 . The method as recited in  claim 13 , wherein the first mixture comprises from 0.01 to 5 wt % inorganic fiber and from 95 to 99.99 wt % water. 
     
     
         19 . The method as recited in  claim 13 , further comprising:
 securing at least one annular layer of facing material to opposing axial faces of the spiral core.   
     
     
         20 . The method as recited in  claim 19  wherein the winding material and the at least one annular layer of facing material each comprise: 75% to 90 wt % inorganic filler; 5% to 20 wt % inorganic fiber; and 1% to 5 wt % organic binder. 
     
     
         21 . The method as recited in  claim 20  wherein the inorganic filler includes talc having a particle size in the range of from 0.2 microns to 1.5 microns.