Usually, For 10BBL/15BBL beer brewery equipment brewhouse unit, we recommend 2-vessel(mash/lauter tun + boiling/whirlpool tun) or 3-vessel(mash tun+lauter tun+ boiling/whirlpool tun). DEGONG fermentation tank can be double wall, and you can choose single wall. Each brewhouse that leaves our facility carries CE,ISO certification and an industry leading 3-year limited warranty on the metal and welds.