Corrosion protection, paper machines

Nonmetallic, composite, and ceramic materials are also used in paper machine construction, particularly on the wet forming end where low friction and dimensional stability are critical. Tile linings are used in tanks and wire pits, and corrosion-resistant coatings are used to protect the carbon steel structural beams in paper machines. 

Furthermore, the biofilm may act as insulation, reducing heat transfer. In the case of heating systems, the efficiency may be considerably reduced [1. Another effect is the reduction of the cruising speed of ships due to increased friction caused by the surfacial biofilm [45]. Finally, biofilm development may cause technical processes to become susceptible to trouble. In paper machines, the inclusion of exopolymers in the pulp may cause the paper web to break in the paper machine. The coating of cans with resins may also be affected. Cans for food are coated on the inside with a resin to protect the metal from corrosion by foodbome acids. If the metal is covered at a few spots with a biofilm (microcolonies), the coating process will not be totally successful. Pores will remain in the resin at these spots, rendering the metal accessible to acids from the food. Corrosion from the inside combined with deterioration and spoilage of the contents will result. 

Corrosion. Anticorrosion measures have become standard ia pipeline desiga, coastmctioa, and maintenance ia the oil and gas iadustries the principal measures are appHcation of corrosion-preventive coatings and cathodic protection for exterior protection and chemical additives for iaterior protectioa. Pipe for pipelines may be bought with a variety of coatiags, such as tar, fiber glass, felt and heavy paper, epoxy, polyethylene, etc, either pre-apphed or coated and wrapped on the job with special machines as the pipe is lowered iato the treach. An electric detector is used to determine if a coatiag gap (hoHday) exists bare spots are coated before the pipe is laid (see Corrosion and corrosion control). 

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