Hi, so i am new to kegging with Sanke Couplers. Tonight I transfered my Chimay Red clone to the 1/6 keg and pitched priming sugar and yeast to re-ferment in the keg. The Sanke keg is used but was still holding pressure when i got it. I have since dissassembled, cleaned and bought a brand new coupler. So heres my problem, after transfering my beer I re-inserted the spear and hooked up the coupler. I hit it with about 10 PSI of C02. I wanted to remove the coupler and let it sit for 2-3 weeks to re-ferment/carbonate naturally. When I twisted the coupler to remove it, the beer started pouring/dumping out of the top. Needless to say it made a huge mess inside my fermentation chamber. I quickly twisted the coupler back on and left the handle in the up position. My question is, what happened? did I do somthing wrong? shouldn't the pressure have sealed the spear valve, making it safe to remove the coupler? Is this a common newbie error? I don't know what to do, I hope the beer isnt ruined? Should I abandon the Sanke keg and transfer to my 5 gal corney keg? I was really excited to start using Sanke kegs "D" style. I tried searching on this site but couldnt really come across anyone with a similar experience. Any help would greatly be appreciated!