Bracelet type sacrificial anode for pipelines - with segments dimensioned to avoid cracks on casting and installation

摘要

Cathodic protection assemblies and sacrificial anodes for cathodic protection of pipelines are claimed. The assembly comprises a 20-70 in. dia. metal pipeline disposed in an electrolyte and provided with a sacrificial bracelet-type anode. The anode comprises an even number in the range 4-8, of anode segments, there being 4 segments for a 20-36 in pipe dia., 6 segments for a 30-54 in dia. 8 segments for a 40-72 in. dia. 4 or 6 segment for a 30-36 in dia., and 6 or 8 segments for a 40-54 in dia. Each segment of anode metal has a cathodic metal core which extends from opposite ends of a segment for joining the segments. Fracture of the segments during cooling after casting and during installation is minimised by having a segment max arc length of 14-27 in., a ratio of segment thickness to pipe dia of 1:5-15 for a 20-36 in. pipe dia or 1:10-20 for a 37-72 in pipe dia., and a ratio of segment width to core width of 2-5:1. The design minimises distortion on casting the segments so that the segments fit closely about the pipeline without having to bend the segment. Thus facturing of the segments is avoided.