Expansion vessel as a pressure fermenter?

[OzzyPeeps]

Hey all,

Im wondering if it would be possible to convert an expansion vessel for a home heating system into a large capacity pressure fermenter (100 liter plus)

I can tig weld so connections are not an issue

I guess Im wondering what the interior of such vessels are lined with?

Can you get them in copper or stainless?

Any plumbers around?

Cheers

X

 

[bracconiere]

i lived in a house with a bladder tank for drinking water from a well for a while? so i think it's be safe for drinking? i don't know how you'd clean it though?

 

[bruce_the_loon]

Iffy to me.

Here is one specification document with some good detail on the internal design. https://www.caleffi.com/sites/default/files/file/01079_en.pdf

Looks like there is an internal bladder that may be EPDM, butyl or styrene-butadiene rubber. EPDM I know we use for tri-clamp seals, the others I don't know.

As to using them as a pressure fermenter, they are rated for 6 to 10 bar, so they should contain the fermentation pressures without a problem. However, that is the pressure rating for the bladder and not the containing tank. You would have to ferment in the bladder and cleaning that might be a major chore.

 

[OzzyPeeps]

Was thinking about tearing the bladder out.

All i really want is a 100 liter plus vessel that will take pressure

 

[bruce_the_loon]

Most appear to be normal steel with no indication of lining inside besides the bladder. Possibly it is galvanized as the connections are listed as such. Definitely not suitable for fermentation. If the internal surface is powder-coated like the outside surfaces, it might be okay.

I did find a couple of 304 stainless steel expansion tanks in your desired range, but they seem to be in the $6000 to $7000 price range. Pressure capable conical fermenters can be found in the $1500 to $2500 range.

 

[OzzyPeeps]

Pressure capable conical fermenters can be found in the $1500 to $2500 range.

But only around the 10-15 gal capaicty mark for the ones I can get in europe AFAICT