Wetted parts for check valve 80%-98% nitric acid application: alloy 20. 2

[hsbcn]

Our customer is looking to substitute the wetted parts of some swing check valves, currently in 316L. For obvious reasons, the 80%-98% nitric acid solution at 20ºC is making the 316L is melt away like butter on toasted bread.

We're looking to substitute these parts with UNS N08020 (Alloy 20); specifically the disc nut, disc washer and hinge pin. Body material is SS310 (see attached GA drawing). Would Alloy 20 be suitable for these particular parts?



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[SJones]

The NACE Corrosion Survey database (COR-SUR) indicates a corrosion rate of less than 0.05 mm/year for 20-Cb3 which would be considered acceptable.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[hsbcn]

Thanks, Steve!

Can you send me a screen shot of that particular table. Client confirms 98% concentration at all times, so the 80-98% range isn't valid.

I work with valves in exotic alloys at The Alloy Valve Stockist. This is our blog, and this is me on Twitter and LinkedIn. Let's connect!