Material for plate and frame HX

[FBiNL]

Anyone with experience with AL6XN or Sea-Cure for stamped plates for PFHX? Currently use Ti in 8 PFHXs in brackish water service. Plates are .5mm thick and about 7 feet tall. Need to replace due to wear and tear from opening and cleaning the HX. Ti is now terribly expesnive, but the vendor has never worked with 6% moly SS or Sea-Cure. Other options such as 316L SS (no good due to excessive crevicve and underdeposit corrosion in stagnant brackish water), Hastelloy (no good due to cost = Ti), and 254 SMO (no good due to chlorination of the liquid system) have been checked. Thanks for any info or contacts.

Dave Murphy (aka Fossil Boy in Nuke Land)
Constellation Energy

 

[EdStainless]

There are a lot of small stamed plate HXs that are made from SeaCure and AL29-4C. Of the two, 29-4C has slightly better corrosion resistance, but SC will form better.

What is on the other side of the HX?

AL-6XN would be a lot easier to work with (it handles like strong 316L) and it is measurably better than 254SMO in crevice corrosion resistance, and it has a long track record in condenser service.

6XN is the safest route from the stand point of forming the plates and such, but SeaCure would get you better thermal properties, better corrrosion resistance, and lower cost.

You only get rewarded for taking risks.

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