GB619950A - Corrosion preventing means for ferrous metal water tanks - Google Patents

Abstract

619,950. Preventing corrosion. TRIGGS, W. W. (McGraw Electric Co.). Oct. 1, 1945, No. 25450. [Class 123(i)] An electrolytic protective device for iron hot-water tanks comprises a magnesium rod 29, Fig. 3, which is suspended from the top of the tank 11 by a metal support 25 and an intermediate block 35 of insulating material, the block 35 being provided with a screw-threaded thimble 37 at each end, for engagement respectively with the end of the support 25 and a reduced end portion 31 of the rod 29, and having embedded therein a resistor 39, of at least 5 ohms, the ends of which are electrically connected to the two thimbles 37. The rod 29 may be in one length, or, alternatively, constituted by a number of pivotally-connected short lengths. The device is preferably disposed axially, the support 25 depending from a hot-water outlet fitting 21, and the .lower end thereof may be secured to a perforated metal baffle on the bottom'of the tank, over a cold-water inlet pipe, by an insulating block similar to the block 35, but, if desired, a plurality of such devices, peripherally spaced from each other on a circle of relatively small diameter, are used. Fig. 6 shows the magnesium rod 91 suspended by a resistor member 89 having an enlarged spherical end 87, and in a modification, Fig. 7, the upper end 63 of the magnesium rod 65 is secured within a hot-water outlet fitting 51, with the interposition of fluid-tight insulating material 59, 61, by a nut 67 and is electrically connected thereto by a resistance wire 69.