| 摘要 |
<p>PURPOSE:To know the condition of generating invisible blisters and corrosion in metal pipe by giving a conductivity to make the electric resistance converted by permeating a liquid in the pipe to a synthetic resin layer, in a complex tube made by covering the inner surface of a metal pipe with a synthetic resin layer. CONSTITUTION:There are formed a metal pipe 10 of aluminum or the like, an insulating layer 40 to cover the inner surface, a synthetic resin layer 20 to cover the inner surface, and a synthetic resin layer 30 to cover the peripherial surface of the metal pipe 10. The synthetic resin layer 20 at the innermost surface of the metal pipe 10 has an electric conductivity, and copper, iron, aluminum, or the like, or a conductive powder such as carbon black is kneaded in to give this conductivity. As a result, the electric resistance is converted by permeating a liquid in the tube to the synthetic layer, and the generating condition of blisters in the insulating layer, and the corrosive condition of the metal pipe can be inspected easily.</p> |
