| 摘要 |
PURPOSE:To obtain a piping material good in heat resistance, fire retardancy and appearance by providing a resin coating layer using fluoroplastic with a combustion heating value of a specific value or less as a base material and having a film thickness of a specific value range to the outer periphery of a steel pipe. CONSTITUTION:A resin coating layer 2 with a film thickness of 10-1000mum using fluoroplastic with a combustion heating value of 3000cal/g or less, for example, a tetrafluoroethylene resin as a base material is provided to the outer periphery of a steel pipe 1. When the film thickness is below 10mum, uniform coating is difficult and the exposure possibility of the steel pipe 1 is large when the coated steel pipe receives mechanical external force. When the film thickness is made larger than 1000mum, economical efficiency is not obtained and a coating method is restricted only to an extrusion coating method. As the coating method of the steel pipe 1, an extrusion coating method, a powder coating application method, a heat-shrinking method of a shape memory tube and a coating application are possible. |
