Steel tuberculation

Cement-Lined Steel Cement-hned steel pipe is made by lining steel pipe with special cement. Its use prevents pickup of iron by the fluid handled, corrosion of the metal by brackish water, and growth of tuberculation. Threaded pipe in sizes from to 4 in is stocked however, cement-lined pipe in sizes smaller than in is not considered practical for common use. 

Figure 3.12 Heavily tuberculated 3-in. (7.6-cm) outer diameter steel mill water supply line.

Oxygen corrosion only occurs on metal surfaces exposed to oxygenated waters. Many commonly used industrial alloys react with dissolved oxygen in water, forming a variety of oxides and hydroxides. However, alloys most seriously affected are cast irons, galvanized steel, and non-stainless steels. Attack occurs in locations where tuberculation also occurs (see Chap. 3). Often, oxygen corrosion is a precursor to tubercle development. 

A specific waterside problem that affects many economizers is normally one of oxygen corrosion. This affects the internal, carbon steel tube header, first-pass tubes, and primary tube bend areas because these areas first receive cold FW. This form of corrosion commonly results in red oxides, economizer pitting and tuberculation, and potentially premature tube failure. 

Corrosion is the deterioration of metallic structures, usually with the loss of metal to solution. It manifests itself in many ways including rusting, pitting, tuberculation, cracking (or embrittlement) etc. Corrosion is a costly and wasteful process it has been estimated that some 25 percent of the annual production of steel in the United States is for the replacement of material lost to corrosion. ... 

Gallionella 7-10 20-40 Aerobic Iron amd steel, stadnless steels Oxidizes ferrous (and manganous) to feme (and mamganic) promotes tubercule formation... 

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