Flue liner identification... Can anyone tell if this is 904/316 or 904/904?

[carbs for arbs]

Hi all

 

Recently had a stove installed.  We asked for 904/904 flue liner to be used but I'm not sure it has been and am thinking 904/316 might have been used instead.  The data plate just says 904 on it, and the installer doesn't seem to distinguish between the two.  

 

I've attached some photos of an offcut that was left...  Is it possible to tell from these what type it is?  Happy to take more if that would help.  Or is there any other way to tell what it is?   

 

In the third photo you'll see that there are thinner strips of metal that I've peeled back to illustrate the point.  I don't know if that counts as the inner or whether it is an additional layer?  But that is definitely thinner than the outer...  

 

Cheers

 

 

 

 

 

 

 

 

[daveatdave]

[daveatdave]

this is the 316

[daveatdave]

this is the 904 

[Alycidon]

The look varies somewhat between manufacturers.    I think you will have to take your installers word for whats been installed, if he has supplied it then he is liable for the warranty aspects.  If you have the packaging the liner was supplied in that may tell you.

 

904/904 is made up of two layers of stainless 904 grade material,    316/904 has an inner of 904 and the outer is 316.    316 is a lower grade of stainless steel but almost impossible to tell apart.    If you are burning solid fuel most of which will be illegal to sell from Jan 22 then the fumes are highly corrosive,  thats why you want 904 on the inside.   Its not really that important what the outer layer is as its not likely to be in contact with the fumes.  

 

If you are burning wood then 316 on the inside would have been perfectly fine unless attempting to slumber the stove which with a 2022 compliant stove is difficult unless you put wet wood into it.

 

A

[Mik the Miller]

You can't really tell by looking at it. Both are Austenitic stainless steels the difference is 316L has less Nickle and Molybdenum in it so is slightly less corrosion resistant. Therefore you want a flue liner which is 904L on the inside and 316L on the outside.

[Stubby]

Don't forget there is a right way up and a wrong way . You need the little ledges sloping down on the inside so the soot doesn't get trapped . 

[Baldbloke]

Don't forget there is a right way up and a wrong way . You need the little ledges sloping down on the inside so the soot doesn't get trapped . 

I wonder how many self installations got that wrong?

[roys]

9 hours ago, Baldbloke said:

I wonder how many self installations got that wrong?

Ohhhhh