Dual seal barrier fluid for hydrofluoric acid environment

[sirpumpsalot]

Does anyone have a recommendation for a barrier fluid to be used in a dual seal that will be in an anhydrous, gaseous hydrofluoric acid environment? I would like to use Fluorolube, but it causes significant swell in Kalrez orings. The engineer who had this project previous to me tried to use a Royal Purple (RP) product and according to John Crane the RP caused a slip-stick situation that caused the seal to fail. Any assistance would be appreciated.

 

[FOETS]

Check the Parker seals website

http://www.parker.com/o-ring/fcg/fcg.asp

it has a very good compatibility guide that may help for all seal materials compared against Fluorolube
or whatever fluid you choose

 

[sirpumpsalot]

What I am really interested in is what are other people using as a barrier fluid for dual seals in an anhydrous HF environment.

 

[longeron]

RP is usually highly recommended by Crane and the other seal mfgs... Slip stick is usually caused when a highly viscous fluid is between the faces.

 

[Milkboy]

Royal Purple (FDA grade) is a good barrier fluid.

Is your seal a dual bellows seal?
Are you getting slip stick from lack of damping on a bellows I wonder?


-
Milkboy

 

[longeron]

In conjunction with the Plan 52, 53, or 54, most often you will find a Plan 32 with Alkylate or Isobutane to help keep high concentrations of HF from getting near the seal. I think I've seen Isobutane used as the barrier/buffer fluid.

A lot of people are migrating to Nitrogen buffer systems with dry running or lift-off containment seals or outright to dual gas seals. This decreases worries about iron fluorides contaminating the buffer fluid as well as contamination from the flare header.

 

[jet1749]

Using Total Seriola 22 heat transfer oil at the moment but not entirely happy with it. I am also considering using Alkylate