Abstract: A fuel system component used to supply a fuel to a fuel tank or used to discharge the fuel from the fuel tank comprises a first resin layer; and a second resin layer formed in a similar color to that of the first resin layer and configured to include a welding portion that is welded to the first resin layer and an exposed portion that is not adjacent to or in contact with the first resin layer. A belt-like portion is formed on a first resin layer-side and conically shaped surface of the exposed portion of the second resin layer at a distance from a boundary between the welding portion and the exposed portion and is configured to include at least one of a concavity and a convexity extended intermittently or continuously.

Abstract: A fuel system component used to supply a fuel to a fuel tank or used to discharge the fuel from the fuel tank comprises a first resin layer; and a second resin layer formed in a similar color to that of the first resin layer and configured to include a welding portion that is welded to the first resin layer and an exposed portion that is not adjacent to or in contact with the first resin layer. A belt-like portion is formed on a first resin layer-side surface of the exposed portion to be parallel to a boundary between the welding portion and the exposed portion and is configured to include at least one of a concave and a convex extended intermittently or continuously.

Abstract: A filler neck is equipped with a neck main body having a pipe shaped resin inner layer and resin outer layer, and a retainer made of metal mounted so as to cover the edge part of the neck main body. The resin inner layer and the resin outer layer are made of resin materials for which one layer has superior fuel permeability resistance to the other layer. The resin inner layer has a screw part for screwing into a screw part of a fuel cap on the inner wall of the resin inner layer. The retainer has a seal part for sealing between the gasket, and a round cylinder shaped outer circumference protector part. The lower end of the outer circumference protector part is on plane perpendicular to the center axis of the fuel path. The plane includes the screw part.

Abstract: A filler neck is equipped with a neck main body having a pipe shaped resin inner layer and resin outer layer, and a retainer made of metal mounted so as to cover the edge part of the neck main body. The resin inner layer and the resin outer layer are made of resin materials for which one layer has superior fuel permeability resistance to the other layer. The resin inner layer has a screw part for screwing into a screw part of a fuel cap on the inner wall of the resin inner layer. The retainer has a seal part for sealing between the gasket, and a round cylinder shaped outer circumference protector part. The lower end of the outer circumference protector part is on plane perpendicular to the center axis of the fuel path. The plane includes the screw part.