So after getting a bunch of sanke/sankey/sanky-modified soda kegs, I set out cleaning diligently.
Reassembling them, I chose to use the spiral rings that were on the kegs.
For the o-ring on the spear to compress completely, either a industry standard spiral retaining ring needs to be installed or a snap ring can be installed. Without either of these, the spear will not compress and the gas below the oring will leak out.
I like the spiral rings the most since they do not protrude out with ears like the snap rings do. Plus, the spiral rings require no extra tools (snap rings require special pliers). To install the internal snap ring, just insert it into the groove and use the wrench to compress it in.
Since I have YET to see a place online that shows you how to do it, step by step with photos, my roomate and I documented how to do it. Enjoy fellow Sanke users!
Photos by my roommate GreatWhiteSlark
Channel-Lock Wrench (Vise-Grip would also work)
1x O-ring: 1 7/8" OD & 5/8" ID(making it 1/8" thick...) I used a Silicone o-ring for mine(McMaster 9396K215)
1 x SS-316 Internal Spiral Retaining Ring (McMaster #92370A251)
1x 2" bore SS Internal Snap Retaining Ring (Mcmaster #91580A246)
1. Make sure the tabs are aligned properly.
2. Feed 1/2 of ring into the bore (1/2 way is where the slight "bend" in the ring is). It should go all the way in, not restricting the tabs. Notice the end is right after the slot, allowing for quick removal
3. Using your right hand to keep the ring from turning, pull the loose side of the ring with your left hand tight. Use your thumb on the right hand to push the ring into the ring bore. It should "bend out" while inside the bore. Keep holding the end of the retaining ring, not allowing the part that is "bending out" to pop out.