| 摘要 |
PURPOSE:To improve the above mentioned anticorrosion effect without requiring repairing countermeasure, by attaching the sacrifice anode at a position separated a fixed region from the inner tube end of steel tube to be joined by welding along the inner circumference face of the tube and forming polarization of lower electric potential than the steel tube. CONSTITUTION:Plural sacrifice anodes 2 are fixed on the inner circumference of tube along the inner face of the steel tube 1 by furnishing metal fittings. On this occasion, it is important to accurately estimate the damaged extent a of inner face coating after welding and corrosion amount of damaged part and then, the anodes 2 able to sufficently cover the extent a to be expected, are provided. Cylindrical shape is most suitable for the shape and thickness, width or dividing number of the circumference of a circle direction etc., are suitably determined by the condition of use of the tube 1. By the above method, anticorrosive effect is able to highten without requiring repairing countermeasre by preliminaryly equipping the sacrifice anode at the damage expected part, even when the inner coating of the steel tube joint part is damaged by welding heat. |
