Hose Degradation (Oh no!)

Hey everyone!

So, today when we were doing dry-runs in preparation for a deep cleaning, I looked in the sightglass of my recovery tank and I saw some ugly black boogers in the recovery tank.

I have a few hypotheses as to what the black boogers are.

  1. Traces of viton and buna rubber from hose lines, gaskets, or master vapor pump diaphragms degrading.
  2. Pump grease from the motor chamber for the master vapor pumps.

Scenario #2 is obviously a fucking nightmare because those MVPs aren’t supposed to have any grease or oil wetted parts that come into contact with solvent, which means we could have a big problem if that’s the pump.

Scenario #1 is a pain in the ass, but probably not as much of a catastrophe.

Possible causes for scenario 1:

  • Mundane wear and tear, they are a few months old now and the manufacturer’s engineer did recommend we replace them every couple months because degradation is possible.
  • Repeated cleaning with alcohols. The nitrile (buna) rubber lining the hoses is rated as ‘good’ for isopropanol, but not ‘excellent’. We noticed no issue for the first few cleanings, but this is about the fourth now so maybe it’s finally starting to wear through.
  • One or more of our employees may have dropped the ball and used acetone to clean the insides of our buna-lined hoses.

Has anyone else had this issue? Anyone know of a good fix? What’s a good solvent for cleaning the inside of a buna-lined hose without messing it up? Hexane looks good on paper but I have my doubts about whether or not I want to expose our employees to all that hexane for cleaning hoses manually.

We tried flushing them out on the system with butane but have found that it really doesn’t seem to wash them out adequately on its own, and the areas around the nozzles and connections still have some gunk in them too.

They make really nice stainless braided hoses with no rubber lining. Maybe we should get those so that any harsh solvent is fair game during a deep clean. I briefly considered limonene to clean these hoses, but it has the same ‘good/fair’ but not ‘excellent’ rating as isopropanol does on many of the charts I’ve referenced.

This is in a state licensed processing facility so naturally we have to get all of our equipment decontaminated down to part-per-billion detection levels of cleanliness and so we really need a viable fix that won’t degrade our hoses. Or maybe after a few months of use they just do this anyway?

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A good solution is stainless hard lines, they sell ptfe hoses overbraided with stainless, the seals are all metal to metal without any o rings or anything to leak or leach. We do a clean in place procedure by flushing the system with liquid butane, after recovering the solvent we remove the platter and clean it. I hope the product that was contaminated was not distributed.


It’s all going to a distiller so I believe they shouldn’t have trouble cleaning it out.

They even make some all-stainless lines with no PTFE liner on the inside. We have a couple of those in house but not a full set. I’d really love to go all stainless because I know that’ll solve it once and for all.

Our machines are all hard line except where they need to bend/flex/or be disassembled. Rubber is probably not easy to remove, do they know what they’re up against?


Where are people getting there hard lines? Trying to remove ptfe forever chemicals from my system


If you have a rack mount set-up it’ll be easier to have stainless piping going into compression fittings mounted on your rack as your “hard-lines.” Using stainless piping going into compression fittings is what I would do if I had a more stationary system or for aesthetics which will run you up a bit.

Other than that, if you’re trying to save money, I’m sure you can find some all stainless no ptfe lined braided chemical hoses and I recommend getting some that already have barb at the angle you need to make it easier to connect.

could go through grainger or google can help


I highly recommend reading this if you’re going hardline