| 摘要 |
PURPOSE:To obtain a steel pipe covered with synthetic resin superior in corrosion resistance and durability, by a method wherein a synthetic resin sheet whose inside has thermoplastic properties is fixed to the outside of the steel pipe by pressure, heated, fused and then cooled. CONSTITUTION:A steel pipe 1, which as arranged a synthetic resin sheet 2 on the outside, is inserted within a flexible film 4 by arranging the film 4 on the inside of a casing 3. The synthetic resin sheet 2 is fixed to the steel pipe 1 by pressure by pressing the same from the outside by inflating the film 4 by supplying air pressure into a pressurizing chamber 7. On the one hand, pressure bonding of a rubber sheet 13c to the steel pipe 1 is performed by supplying air pressure within an air chamber 13a of sealing equipment 13 also. Air between the steel pipe 1 and the synthetic resin sheet 2 is sucked through decompression of a decompression chamber 16. The synthetic resin sheet 2 is fused in order to the steel pipe 1 through a rotation of the steel pipe 1 and a movement of heating equipment 17 in an axial direction. After completion of fusion, the steel pipe 1 to which the synthetic resin sheet 2 has been fused is removed by releasing pressure of the pressurizing chambers 7, 13a and suspending decompression of the decompression chamber 16 and cooled suddenly through water spray after the lapse of an appropriate radiation period of time. |
