Originally Posted by Floydsview
Has anyone used the above silicone orings for pin-lock's?
Silicone is not a good choice for Corny post Orings, and if used elsewhere in your kegging setup, will just complicate your life with lubricant incompatibilities.
Why silicone is not a good choice for keg posts:
Silicone is only recommended for static placement- like a keg lid or dip tube. It does not hold up well when subjected to dynamic stresses- like removing & replacing keg QDs.
Silicone rubber is not compatible with silicone based lubricants (i.e. "Keg Lube"). A silicone based lube will soften, enlarge, and degrade a silicone rubber Oring making it even more susceptible to dynamic stress damage. This will result in randomly occurring leaks (which I think are more sinister than a leak at initial assembly time).
Silicone is, however, compatible with petrolatum based lubes (Petrol-Gel, Lubri-film, etc.), and they are the most readily available lubes for use with silicone. Buna-n, conveniently, is compatible with both silicone and petrolatum based lubes.
Why you should still care about lubricant incompatibility:
Sankey keg valves (EPDM) and shank/coupler gaskets (Neoprene) are incompatible (highly for EPDM in my experience) with virtually all lubricants made for silicone rubber as most are petroleum based. There are some dual use lubes, but they are prohibitively expensive, hard to source, and have dubious food safiness (any Colbert fans out there?).
So, if you will never encounter EPDM (Sankey), Neoprene (shank/coupler gaskets), or for that matter almost any material besides silicone rubber and Buna-n, you could get away with switching to a single petrolatum based lubricant.
Why there are still no good arguments for using silicone rubber for kegs:
If you have a post that will only seal with a silicone Oring, it would be better to find out why, and fix it. Using a silicone Oring to remedy the situation will likely just cause a random sealing issue after it inevitably fails due to wear.
For dip tubes, given the better sealing properties of the "X-rings" (quad/dual/double seal), and that they have only been found (so far) in Buna-n, there really isn't much of an argument for silicone here either.
For lids, same goes as for posts- find the problem: bent lid, worn feet, bent keg flange,etc., and fix it. (More than likely fixing the issue will make your lids and kegs interchangeable so you don't have a panic situation when you forget which lid goes where with what Oring.) There isn't the danger of dynamic damage with lids, except during handling, but the lubricant issue remains.
Applications where silicone rubber does make sense:
For 'weldless' kettle fittings they are a good choice because of their high heat ratings. It is a static placement, and lube shouldn't be used in this application anyway, so it doesn't cause any lubricant compatibility issues. Although for stainless vessels, getting the fittings welded or soldered is a much better solution- regardless of what Blichmann fanboys have been brainwashed into believing.
Same goes for cam and groove (camlock) fittings. Silicone is a good choice since the fitting may be exposed to high heat; it is (mostly) a static placement; and no lube should be used here either.