CORROSION PREVENTIVE METHOD FOR STAINLESS STEEL PIPING FOR FEEDING WATER FOR MISCELLANEOUS USE

摘要

PROBLEM TO BE SOLVED: To provide a method for preventing the corrosion of the circumferential weld zone of stainless steel by degradation in the quality of water for miscellaneous use when a SUS 304 stainless steel piping is used for a piping for feeding the water for miscellaneous use. ;SOLUTION: This corrosion preventive method consists in maintaining the water for miscellaneous use at the quality satisfying the equation Y-0.02X+40 by adjusting M alkalinity in the case where the concn. of the Cl^- of the water for miscellaneous use is ≥100ppm and the M alkalinity Yppm converted to CaCO₃ deviates from the range expressed by the formula with the Cl^- concn. as Xppm in the stainless steel piping for feeding the water for miscellaneous use. The water for miscellaneous use may be maintained at the water quality at which the pH is ≥3 and the M alkalinity satisfies the above equation by lowering the pH of the water for miscellaneous use.;COPYRIGHT: (C)1998,JPO