I guess my point was that people shouldn't think that expensive, exotic
solutions are required on a hobby rocket.
In the past I've used silicone, fluorosilicone, and EPDM o-rings with
nitrous oxide, but YMMV. I can't remember why Kalrez wasn't used. EPDM
passed impact testing in nitrous oxide, but yes it can burn if an ignition
source is present. Silicone and stainless steels will also burn. It's not
black and white of course, which is why there is so much conflicting
information out there. Silicone and EPDM burn slowly when used as
ablatives, of course fiber loading has a lot to do with that, and now I am
way off topic...
Back to the original question: As far as rapid decompression destroying
o-rings, I've seen fluorosilicone o-rings show damage after hundreds of
rapid 3000 psi cycles (a few seconds each), but it may have been
extrusion/tearing. This was after life testing with hundreds of cycles in a
moving piston type seal with very little lubrication.
-Daryle
On Fri, Aug 21, 2015 at 9:37 AM, Doug Jones <djones@xxxxxxxx> wrote:
EPDM burns merrily in N2O. The only elastomer I've found that neither
swells nor burns is Kalrez.
Doug Jones
On 8/21/2015 5:44 AM, Daryle Dismukes wrote:
Recent tests show that EPDM can also work with nitrous oxide if a more
durable elastomer is required.
-Daryle