Abstract: A fuel tube for a gasoline engine includes an outer polymer layer of polyamide, an inner polymer layer of polyamide, and an intermediate permeation barrier layer of ethylene vinyl alcohol copolymer (EVOH). The permeation barrier layer has an ethylene content of approximately 24 to 29 mol percent and a thickness between approximately 0.02 mm and 0.07 mm.

Abstract: A multi-layer tube for use in a motor vehicle system to transport fluids containing hydrocarbons such as would be found in a fuel line, a vapor return line or a vapor recovery tube having a first layer radially disposed innermost made up of an extrudable melt-processible thermoplastic material capable of withstanding prolonged exposure to automotive fuel and various fuel additives, and second layer made up of an extrudable, melt-processible non-polyester, non-alcoholic thermoplastic material capable of sufficiently permanent laminar connection with the first layer so as to prevent delamination between the first and second layers during a desired lifetime of the tube.

Abstract: A multi-layer tube suitable for use in a motor vehicle system to transport fluids containing hydrocarbons such as would be found in a fuel line, a vapor return line or a vapor recovery tube having a first layer radially disposed innermost made up of an extrudable melt-processible thermoplastic material selected from the group consisting of aromatic polyketones, aliphatic polyketones and mixtures thereof, and second layer made up of an extrudable, melt-processible thermoplastic material capable of sufficiently permanent laminar adhesion with the first layer so as to prevent delamination between the first and second layers during a desired lifetime of the tube, and a third layer overlying the first layer made up of a melt-processible thermoplastic material such as polyamides, high density polyethylenes and mixtures thereof.

Abstract: A tube having a cylindrical main body and a thin wall defined by an inner surface and outer surface. The tube includes a first segment having a generally constant cylindrical cross-section and another segment having a variable cross-section containing convolutions to allow for flexing of the tube during installation. The convolutions extend less than the entire circumference of the tube or have tapered side walls which substantially reduce the size of the convolutions as the convolutions extend from one position along the circumference to a second position.