Conduit for conveying petrochemical products

摘要

The piping to carry petrochemical media, such as a motor fuel line, has an inner tube (1) of plastics or metal held concentrically by a distance holder (2) within a plastics outer tube (4,5). The outer tube (4,5) has a layer (4) of a material which is impermeable to the diffusion of a liquid or gas. The layer (4) is an aluminium foil with a copolymer coating, or a film of ethylene vinyl alcohol (EVOH), polyamide and an ethylene vinyl alcohol/polyamide compound.