Low permeability elastic sealing ring

A piping assembly, comprising:

• a fuel supply hose that extends in an axial direction and that has an open end, an outer surface and an inner peripheral surface;
• a companion pipe that has a leading edge that is inserted into the open end of the fuel supply hose so that the fuel supply hose overlaps the companion pipe in a direction that is radial to the axial direction;
• an annular protuberance that protrudes outwardly from the companion pipe in the radial direction, wherein the fuel supply hose overlaps the annular protuberance in the radial direction;
• one annular ring groove formed in the inner peripheral surface of the fuel supply hose, wherein the annular ring groove overlaps the companion pipe in the radial direction;
• exactly one elastic sealing ring disposed in the annular ring groove, wherein the elastic sealing ring has an inner core layer that is formed from a material possessing low temperature-resistance characteristics in order to maintain high elasticity at low temperature and an outer layer covering the inner core layer and formed from a material possessing impermeability to fuel;
• and
• a clamping member that is clamped on the outer surface of the fuel supply hose at a location that is proximate the open end;
• wherein the elastic sealing ring is pressed between the fuel supply hose and the companion pipe at a location between the leading edge and the protuberance to form a seal between the fuel supply hose and the companion pipe;
• and
• wherein the annular ring groove, protuberance and clamping member do not overlap in the radial direction and wherein the protuberance is located between the annular ring groove and the clamping member in the axial direction.