AFAIK they are completely phased out in the soda industry (including McDs). They are very popular in the home beer brewing community because they are easy to clean and the right size for your typical homebrew batch (20 litres). They've become difficult to obtain in recent years because they are not being used in industry any more so there's no secondary market.
Some players are making them new, but they are quite expensive. I used to have a couple of regular beer kegs on "long term loan" from Heineken because I was not able to source cornys for cheap.
Comments
You are referring to Corny kegs [1].
AFAIK they are completely phased out in the soda industry (including McDs). They are very popular in the home beer brewing community because they are easy to clean and the right size for your typical homebrew batch (20 litres). They've become difficult to obtain in recent years because they are not being used in industry any more so there's no secondary market.
Some players are making them new, but they are quite expensive. I used to have a couple of regular beer kegs on "long term loan" from Heineken because I was not able to source cornys for cheap.
1 - https://en.wikipedia.org/wiki/Cornelius_keg