well i tried this w/ my rectangle 58 quart. first, the ball valve, actually ends up w/ part of it inside the cooler, because the nipple seems too short for my cooler. I drip tested it, and it leaked, since i had no room for a washer in between the rubber gasket and the barb adaptor, so there wasnt enough of a seal. I managed to squeeze a washer in there, but it of course made the ball valve go deeper in the cooler...but now no drip.. i mean its functional as it is, and i can work the valve..but should i get a longer nipple?
Also, they didnt have stainless steel fender washers, only zinc coated..is that ok and safe to use?