316 versus 904 liners

[jtcedinburgh]

Just curious - why is 904 grade stainless suitable for smokeless solid fuels (briquettes) but 316 not? I only have a 316 grade liner, and I've now read that using smokeless solid fuels with it is not recommended - why is this? Is it the nanny state at work, or some covert means of getting us all to buy more expensive 904 grade liners. Should I be concerned?

john

 

[webbie]

I never heard of 904 stainless!

It is not common here in the US. Common grades for solid fuels include 304, 316 and various 400 series. For condensing units, AL-29-4C is used - it is less likely to pit from salt and acids.

904 appears to have a higher nickel content and also come copper. Perhaps Metal can explain, but my guess is that it is an expensive alloy designed to resist acids.

Keep in mind that we don't have "smokeless fuels" in the usa - at least in the general sense. My guess is that in Europe these are made with a number of different materials, from coke to peat, and therefore might have acid problems. Doing a search on 904 shows very few references.....it appears to be almost an exotic alloy.