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Treating SS pipe for use as bio-mass stove exhaust

I am designing exhaust pipe for bio-mass fuel stoves. Hydrochloric acid and potassium chloride have been detected in the exhaust and they're corroding the 304 SS pipe. What would be the most corrosion resistant yet cost effective method to deal with this? Should the pipe be passivated? Should another grade of stainless steel be used? Is there a coating specific for this type of application? The pipe will see temperatures around 700 degrees F near the stove outlet. Any suggestions would be most helpful.

Jane Fier
Design Engineer - Minneapolis, Minnesota, USA
2004

This is a difficult atmosphere for stainless steel. The chlorides are difficult on any stainless steel, but 304 will definitely not hold up with chlorides at these temperatures. You need to go to at least 316L or 318 to get near enough resistance, and it MUST be passivated to hope for success.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2004

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