Sealing system and gasket therefor

Abstract

A sealing system ( 1 ) comprising an at least substantially cylindrical tube ( 2 ) and at least two sealing collars ( 4 ) at least partially made of an elastic material, which are arranged round the tube in spaced-apart relationship for sealing confinement by collaring of the tube in a bushing ( 3 ) which is co-axial with said tube, a special feature being the fact that the spacing (a) between the sealing collars is less than 25 mm, said sealing collars comprising an expandable material, in such an amount and of such a composition that the sealing collars will expand in the case of a fire, in such a manner that they will become wedged in the bushing.

1 . A sealing system comprising an at least substantially cylindrical tube and at least two sealing collars at least partially made of an elastic material, which are arranged round the tube in spaced-apart relationship for sealing confinement by collaring of the tube in a bushing which is co-axial with said tube, characterized in that the spacing between the sealing collars is less than 25 mm, with said sealing collars comprising an expandable material, in such an amount and of such a composition that the sealing collars will expand in the case of a fire, in such a manner that they will become wedged in the bushing.  
     
     
         2 . A sealing system according to  claim 1 , wherein the spacing between the sealing collars is less than 20 mm, in particular less than 15 mm, more in particular 10 mm or less.  
     
     
         3 . A sealing system according to  claim 1  or  2 , wherein the sealing collars comprise circular outer ribs and circular inner ribs, which outer ribs have an outside diameter which is larger than the inside diameter of the bushing, and wherein the inside diameter of the inner ribs is at most substantially equal to the outside diameter of the tube.  
     
     
         4 . A sealing system according to  claim 1 ,  2  or  3 , wherein the sealing collars each comprise at least two shell members, whose abutting boundary surfaces extend at least substantially in axial direction, wherein the rear flanks, seen in the direction of insertion, of the outer, serrated ribs extend in radial direction and the inner ribs are arranged in pairs in the radial area of the outwardly extending tips of the outer serrated ribs.  
     
     
         5 . A sealing system according to any one of the preceding claims  1 - 4 , wherein the inner ribs of the sealing collars are trapezoidal in shape, seen in the direction of the axial longitudinal section.  
     
     
         6 . A sealing collar apparently suitable for use in a sealing system according to any one of the preceding claims  1 - 5 .