Gasket

Abstract

A gasket for fluidly sealing two conduits having mating surfaces is described. The gasket includes an outer seal with a first thickness and an inner seal with a thickness greater than that of the outer seal. The inner seal can be compressed at least to the thickness of the outer seal. Methods of making the gaskets are also disclosed.

What is claimed is: 
     
         1 . A gasket for fluidly sealing two conduits having mating surfaces, comprising:
 a core comprising top and bottom surfaces comprising a series of serrations;   two sealing layers capable of fluidly sealing two conduits, wherein the core is between the two sealing layers;   a deformable material capable of fluidly sealing two conduits, wherein the deformable material is adjacent to and radially inward from the sealing layers;
 wherein the deformable material has a thickness measured from a top surface to a bottom surface of the deformable material that is greater than a sealing layer/core thickness measured from a top surface to a bottom surface of the sealing layers; and 
 wherein the thickness of the deformable material can be deformed at least to the sealing layer/core thickness. 
   
     
     
         2 . The gasket of  claim 1 , wherein the deformable material is secured to the core. 
     
     
         3 . The gasket of  claim 1 , further comprising a projection extending radially inward from a core inner surface and into the deformable material, wherein the projection secures the deformable material to the core. 
     
     
         4 . The gasket of  claim 1 , wherein the deformable material has a compressability of 30% to 90%. 
     
     
         5 . The gasket of  claim 1 , wherein the deformable material is more compressible than the sealing layers. 
     
     
         6 . The gasket of  claim 1 , wherein the deformable material comprises polytetrafluoroethylene (PTFE). 
     
     
         7 . The gasket of  claim 1 , wherein the deformable material comprises expanded PTFE. 
     
     
         8 . The gasket of  claim 1 , wherein the core comprises stainless steel, a Monel alloy, or carbon steel. 
     
     
         9 . The gasket of  claim 3 , wherein the projection comprises stainless steel, a Monel alloy, or carbon steel, and wherein the core comprises the same material as the projection. 
     
     
         10 . The gasket of  claim 1 , wherein the two sealing layers comprise PTFE, graphite, a vermiculite-based sealing material, non-asbestos sheet, or soft metallic face. 
     
     
         11 . The gasket of  claim 1 , wherein the gasket further comprises a chemical treatment agent within the deformable material, and wherein the chemical treatment agent is in contact with at least one mating surface when the gasket is compressed by the mating surfaces. 
     
     
         12 . The gasket of  claim 11 , wherein the chemical treatment agent comprises a corrosion treatment agent. 
     
     
         13 . The gasket of  claim 11 , wherein the chemical treatment agent is present in the deformable material in a range of 0.01% to 50% w/w. 
     
     
         14 . A gasket for fluidly sealing two conduits having mating surfaces, comprising:
 an outer sealing means for compressibly forming a seal between two fluidly connected conduits; and   an inner sealing means for compressibly forming a seal between two fluidly connected conduits,
 wherein the inner sealing means is radially inward from the outer sealing means, 
 wherein the inner sealing means comprises an uncompressed thickness greater than an uncompressed thickness of the outer sealing means; and 
   wherein the inner sealing means is deformable from the uncompressed thickness of the inner sealing means at least to the uncompressed thickness of the outer sealing means.   
     
     
         15 . The gasket of  claim 14 , wherein the outer sealing means comprises a rigid core between two or more sealing layers. 
     
     
         16 . The gasket of  claim 14 , wherein the inner sealing means comprises a projection from the rigid core into one or more deformable materials. 
     
     
         17 . The gasket of  claim 14 , wherein the inner sealing means is more deformable than the outer sealing means. 
     
     
         18 . The gasket of  claim 14 , wherein the inner sealing means comprises expanded polytetrafluoroethylene (PTFE). 
     
     
         19 . The gasket of  claim 14 , wherein the outer sealing means comprises strength increasing means for improving sealing. 
     
     
         20 . The gasket of  claim 14 , wherein the gasket further comprises a chemical treatment agent within the inner sealing means, and wherein the chemical treatment agent is in contact with at least one mating surface when the gasket is compressed by the mating surfaces. 
     
     
         21 . The gasket of  claim 20 , wherein the chemical treatment agent comprises a corrosion treatment agent. 
     
     
         22 . The gasket of  claim 20 , wherein the chemical treatment agent is present in the inner sealing means in a range of 0.01% to 50% w/w. 
     
     
         23 . A gasket for sealing opposing flange surfaces of a pipe having corrosive fluid flowing there through comprising:
 a serrated profile core comprising a core thickness and a core inner surface;   a projection extending radially inward from the core inner surface;   a deformable material around the projection,
 wherein the deformable material extends radially inward from the core inner surface, inward beyond the projection such that the deformable material defines a gasket inner surface; and 
 wherein the deformable material comprises a thickness greater than a thickness of the core. 
   
     
     
         24 . The gasket of  claim 23 , wherein the core comprises stainless steel, a Monel alloy, or carbon steel. 
     
     
         25 . The gasket of  claim 23 , wherein the deformable material comprises expanded PTFE. 
     
     
         26 . The gasket of  claim 23 , further comprising sealing layers on the top and bottom surfaces of the serrated profile core. 
     
     
         27 . The gasket of  claim 26 , wherein the sealing layers comprise PTFE, graphite, a vermiculite-based sealing material, non-asbestos sheet, or soft metallic face. 
     
     
         28 . The gasket of  claim 26 ,
 wherein the sealing layers and the core form an outer portion,   wherein the deformable material and the projection form all or part of an inner portion,   wherein when the outer portion and the inner portion are secured between opposing flange surfaces and deformed to an in-use thickness, the deformation of the inner portion is greater than the deformation of the outer portion.   
     
     
         29 . The gasket of  claim 28 , wherein the inner portion is capable of forming a fluid seal between the gasket and the opposing flange surfaces. 
     
     
         30 . The gasket of  claim 28 , wherein the outer portion is capable of forming a fluid seal between the gasket and the opposing flange surfaces.