I just got a sixth barrel sanke keg. I am new to this style keg but I have removed the retaining ring from the valve and disassembled the keg properly and understand how it works. My question is about the retaining ring that holds the valve and stem in the keg. I can't seem to find them online to purchase a new ring. And I also would like to know if I can reuse the ring I removed? If anyone could please share with me a place that sells the retaining ring or give me any advice on use for the keg I would appreciate it.