Fluid that causes fast degridation in O-Ring
Fluid that causes fast degridation in O-Ring
(OP)
Trying to see if there is anyone out there that is aware of a fluid that will degridate the rubber in an o-ring seal [say NBR].
I`m not looking for the oring to swell, infact the opposite, be eaten !! Thus that the seal provided by the oring will be lost ....
Anyone any ideas ?? I`m told my skydol might do what I`m looking for with a Fluorocarbon oring ???
I`m not looking for the oring to swell, infact the opposite, be eaten !! Thus that the seal provided by the oring will be lost ....
Anyone any ideas ?? I`m told my skydol might do what I`m looking for with a Fluorocarbon oring ???





RE: Fluid that causes fast degridation in O-Ring
Skydrol, or even brake fluid, will cause swelling with a fluorocarbon elastomer.
Try here: http://www.parker.com/o-ring/fcg/fcg.asp
RE: Fluid that causes fast degridation in O-Ring
Look here:
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You should actually test whatever combinations seem promising, because it's not customary to record the degree to which a combination is unsatisfactory in seal/fluid testing.
Mike Halloran
Pembroke Pines, FL, USA
RE: Fluid that causes fast degridation in O-Ring
I could use heat, but I really want to achieve distruction of the seal through chemical means !!
Thanks so far, just hoping someone knows a good combination.
RE: Fluid that causes fast degridation in O-Ring
RE: Fluid that causes fast degridation in O-Ring
Mike Halloran
Pembroke Pines, FL, USA
RE: Fluid that causes fast degridation in O-Ring
Iam not sure what it is you are trying to do?
Use a fluid that will deteriorate an O-ring or.
Find an O-ring that will not deteriorate?
Which is it?
pennpoint
RE: Fluid that causes fast degridation in O-Ring
buna n and use all and checkout the results.
http://www.coleparmer.com/techinfo/chemcomp.asp
RE: Fluid that causes fast degridation in O-Ring
I think I have three options to stop this seal working -
1. Drill through the steel to the ORing.
2. Use excessive heat to deteriate the ORing.
3. Chemically eat the ORing.
3 seems like the niest option thus I`m trying to find the best combintation of rubber and fluid to achieve this.
I was trying to reduce the amount of guess work to trying different fluids and rubbers, by seeing if anyone out there had done something kind of strange like this before !!
RE: Fluid that causes fast degridation in O-Ring
RE: Fluid that causes fast degridation in O-Ring
RE: Fluid that causes fast degridation in O-Ring
A time frame for this failure to happen has not been revealed. If the time frame is 'quickly', that suggests the option of using any arbitrary fluid and simply omitting the o-ring from the assembly.
Mike Halloran
Pembroke Pines, FL, USA
RE: Fluid that causes fast degridation in O-Ring
First I need a seal for which the ORing is there doing it`s normal job, then I need to remove this sealing point, thus I was looking for some bright sparkle that might know a combination of ORing [Nitrile, Viton, Aflas etc] and fluids that they have seen being pretty distructive !!!
As you point out I did not really give a good answer for time period, I`m taking a good stab and I think 72hour would be acceptable.
I guess it look like I`m just gonna try some combinations myself.
RE: Fluid that causes fast degridation in O-Ring
An O-ring compound combination that might work is to use EPDM rings where you want them to stay put, and polyacrylate or polyurethane for the "dissolvable" ring. Test with water, then dissolve/destroy the poly ring using a strong acid or base solution. You will need to test the solvent to make sure you get the right reaction, and may need to use heat to completely destroy the poly ring in 72 hours.
RE: Fluid that causes fast degridation in O-Ring
Good Luck
RE: Fluid that causes fast degridation in O-Ring
RE: Fluid that causes fast degridation in O-Ring
Some fluids do weaken the elastomers like methanol and glycol at a certain pressure/temperature combination. But also water at higher pressure temperature combinations may harm o-ring seals.
Another important matter is the AED (Anti Explosive Decompression) phenomenon. Gasses will integrate in the o-ring material at high pressure over the time, and when the pressure drops the o-ring will crack, due to the extrusion of the gas (CO2 is one of those gasses which easily integrate into the elastomers).
If an application requires as such, you should order O-ring materials with AED, but realize there are a lot of different grades AED within the industry. James Walker have reliable grades.
Regards.
RE: Fluid that causes fast degridation in O-Ring
A plastic material might be easier to decompose than a cross-linked elastomer, but then you don’t get the resilience of the rubber. – Introducing some means of imparting mechanical damage seems the only real way to “break” the seal in-situ.
FKE has a point regarding E-D – you might be able to take a mechanically relatively weak rubber compound (silicone for example) and introduce a gas such as CO2 at very high pressure, then suddenly release the pressure causing the entrained gas to burst and split the seal. You might need to repeat this process several times to be sure that the damage has occurred (e.g. it will no-longer hold pressure). This of course depends on what pressure the housing is intended for in the first place.
RE: Fluid that causes fast degridation in O-Ring
Fit a plug of a low melting point alloy (bismuth-tin-lead e.g. Rose's alloy etc.)into the body of the unit under the seal position before you machine the O-ring grove. You only need to then heat it to a relatively low temperature, and the plug melts away and leaves a bypass groove beneath the seal.