Metal finishing Q&As since 1989

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Chloride Corrosion in SS 304L piping in Sugar Refinery

What will be the impact of Chloride Corrosion in SS 304L piping and tanks to be used for Proposed Sugar Refinery. Particularly for sugar massecuite and magma liquids being pumped and stored in tanks between processes at around 50 to 70 °C. What should be the most suitable materials for this service.

S.A.MANSOOR
Director Technical, - DHAKA, BANGLADESH
2004

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304L is not very resistant to chlorides. 316L is better. There is not enough information here to be able to judge the potential effect of the chloride on the 304L. It depends on concentration, time, condition of the tanks, etc. IF the concentration is high it could pinhole through the tank quite easily at this temperature. Talk to your steel supplier. I am not familiar with the formulation of these sugar producing compounds.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2004

Please know that essentially every Stainless grade (300 series)will suffer attack by chlorides at some level of: a)chloride concentration, b) acidity, and c) temperature. I suspect, but of course do not know, that type 304L was recommended to you because it has been used successfully in other similar applications. Past experience is usually the best guide. There are process industry publications that should tell what grade of Stainless is recommended for sugar refinery use, but I would recommend specifying a 9% minimum nickel chemistry if T304L is decided upon.

Ray B Anderson
- Kent, Ohio
2004