| 摘要 |
PURPOSE:To perfectly remove fats and oils stuck to the inner surface of a large diameter steel pipe in one washing. CONSTITUTION:In a manufacturing method for large diameter steel pipe 2, succeeding to an expanding process for the diameter of the pipe, by spraying high alkaline washing solution 9, the inner part of the pipe is washed. Successively, after executing a hydraulic test, by spraying pure water, the inner surface of the pipe is washed with water and this pipe is conveyed to a beveling process in the pipe end. Thereafter, this pipe is conveyed to a coating process in the inner surface of the pipe through a shot blast treatment process in the inner surface of the pipe without passing through each process of washing and drying in the inner surface of the pipe. |
