Patent ID: 7111646

Claim:
A multilayer resin pipe of multilayer construction comprising a plurality of resin layers made of thermoplastic resins, wherein at least the innermost layer is a low-permeability resin layer, and at least one of the resin layers is an electrically conductive resin layer made of a resin matrix containing electrically conductive filamentous filler; wherein elements of the electrically conductive filamentous filler have lengths not shorter than a minimum length determined on the basis of an expected elongation percentage and an expected working length of the multilayer resin pipe, and wherein the elements of the electrically conductive filler have lengths greater than the product of the expected elongation percentage and the expected working length so that the filamentous filler of the electrically conductive resin layer is not broken and the electrically conductive resin layer maintains its electrical conductivity in the event the matrix of the electrically conductive resin layer swells.