Connecting piece for multilayered conduits, method of connecting, and assembly obtained by the method

Abstract

Coupling piece for an outer end of a multilayered conduit, comprising a coupling pipe which is provided on the outer side with a radially upright wall, wherein the wall is widened in axial direction at a radial distance from the outer side of the body, wherein the outer side of the coupling pipe, the upright wall and the widened portion enclose an annular insertion space into which the outer end of the conduit can be directly inserted, and wherein the radial distance between the widened portion of the wall and the outer side of the coupling pipe at the position of the entry to the insertion space is such that it is equal to or greater than the wall thickness of the conduit, wherein an inner diameter of the coupling pipe increases in outward direction at the exit.

1 . (canceled) 
     
     
         2 . Coupling piece for an outer end of a multilayered conduit, comprising:
 a coupling pipe, which is provided on an outer side with a radially upright wall, wherein the wall is widened in an axial direction at a radial distance from the outer side of the coupling pipe, wherein the outer side of the coupling pipe, the upright wall and the widened portion enclose an annular insertion space, into which the outer end of the conduit can be directly inserted, and wherein the radial distance between the widened portion of the wall and the outer side of the coupling pipe at a position of entry for the conduit into the insertion space is equal to or greater than the wall thickness of the conduit,   wherein an inner diameter of the coupling pipe increases in outward direction at the exit.   
     
     
         3 . Coupling piece as claimed in  claim 2 , wherein the widened portion is smaller in the axial direction than an axial length of the coupling pipe as measured from the upright wall towards an outer end of the coupling pipe. 
     
     
         4 . Coupling piece as claimed in  claim 3 , wherein the widened portion is smaller than the coupling pipe by a factor of 4 or more. 
     
     
         5 . Coupling piece as claimed in  claim 2 , wherein an outer diameter of the coupling pipe is substantially constant in an outward direction at an exit or reduced at the exit. 
     
     
         6 . Coupling piece as claimed in  claim 5 , wherein the outer diameter of the coupling pipe is substantially constant from the annular insertion space to the exit. 
     
     
         7 . Coupling piece as claimed in  claim 2 , wherein an inner wall of the coupling pipe is reinforced with an adjacent reinforcing layer of reinforced plastic or of metal which has a greater strength than the material of the coupling pipe. 
     
     
         8 . Coupling piece as claimed in  claim 7 , wherein the reinforcing layer is provided with engaging elements, while the inner wall is provided with connecting elements which correspond with and connect to the engaging elements. 
     
     
         9 . Coupling piece as claimed in  claim 2 , wherein the annular insertion space narrows in a direction of the wall, such that the radial distance between the widened portion of the wall and the outer side of the coupling pipe decreases to a value smaller than the wall thickness of the conduit. 
     
     
         10 . Coupling piece as claimed in  claim 2 , wherein the upright wall and the widened portion have a T-shaped cross-section. 
     
     
         11 . Coupling piece as claimed in  claim 2 , wherein the coupling piece is formed substantially integrally. 
     
     
         12 . Coupling piece as claimed in  claim 2 , wherein the coupling piece, and the reinforcing layer thereof, is formed substantially from material comprising PE, reinforced PE or PE-RT. 
     
     
         13 . Method for coupling an outer end of a multilayered conduit to a coupling piece as claimed in  claim 2  by polyfusion welding,
 wherein the method comprises the steps of heating contact surfaces of the coupling piece and of the outer end of the conduit, joining the contact surfaces and, after fusion, allowing the obtained fused connection to cool, wherein between conduit and coupling piece a connecting weld rib is obtained which protrudes from the annular space. 
 
     
     
         14 . Assembly of a multilayered conduit with a coupling piece obtained via the method of  claim 13 , wherein between the conduit and the coupling piece a connecting weld rib protrudes from the annular space.