What is the goal here? I've never seen something like this...
I probably won't do it, but I'm considering buying one of these:http://www.ssbrewtech.com/products/brewbucket
Or maybe one of these:http://www.ssbrewtech.com/products/the-brewmaster-bucket
I was thinking that if I could attach a corny gas post to the airlock stopper, I could pump in a few psi of CO2 prior to cold crashing to avoid air getting sucked into the fermentor (I've heard from other owners that the brewbuckets can hold about 4 psi before the lid seal begins to leak).
I was also thinking that I could do closed loop transfers to a purged serving keg by positioning the brewbucket above the keg, attaching a hose from the fermentor racking arm to the liquid out post on the receiving keg, and attaching a hose from the gas in post on the receiving keg to the airlock gas in post on the fermentor.
I ferment in 10 gallon corny kegs now which is nice because I can cold crash and transfer under pressure without exposure to air. The brewbuckets have a few advantages over fermenting in cornies, but I want to retain these abilities.