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The following are excerpts from the NACE International Corrosion Network (NCN) and NACE Coatings Network. These are e-mail-based discussion groups for corrosion professionals, with more than 3,000 participants.
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Scale deposits in a steam turbine
process compressor. We ob- served scale deposits on the
Q
internals. The scale deposits were white-colored and suspected to be sodium salts. Unfor- tunately, all the deposits were inadver- tently washed away and we could not analyze them. The peculiar observation that we made was that the deposits were found only between the inlet of the steam pipe
Recently we opened the high-pressure steam turbine that drives our centrifugal
and the turbine's extraction point. The white deposits were not found in any other place past the extraction point in any of the turbine blades. Also, we have not noticed any pitting damage caused by the deposits. Does anyone have experience with such scale deposits who could guide us to determine its source? We seriously doubt that our steam has severe problems caused by deposits. Can it be a one-time phenomenon associated with the tur- bine's shutting down process?
caustic. The caustic was carried into the condensate return and then was injected Continued on page 12
A
I once consulted with a gas plant that experienced a relatively se- vere contamination of a 30-psi (207-kPa) steam system with
NACE International, Vol. 51, No. 4
April 2012 MATERIALS PERFORMANCE 11
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