Butane liquid transfer pump

Hash and Stuff Extraction
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Yea the beaker and wrench ones lol

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Haskel sent us a re-engineered pump. it leaked.

doesn’t look like they even thought about the problem based on WHERE it leaked.

O-ring’s on inlet and outlet failed because of the temps…

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Seems like ptfe here might solve it…

(... and the solvent in the tube goes round and round)

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I’m afraid not, those boss sae fittings are not thread sealed and PTFE makes a terrible low temp seal. I’d say FKM or perhaps polyurethane. There are some elastomers designed for low temps (different plasticizers) but they’re $$$

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I heard Gylon is the current best one for extraction.

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That’s just pure PTFE. Again, PTFE is not an elastomer and is prone to becoming brittle when cooled. It also shrinks faster than the stainless, allowing leaks to happen (versus an elastomer that has some squish to make up the difference as it shrinks). Great for chemical compatibility, not good for large temperature changes or low temps.

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126

Looks like there is enough flat there for a bonded metal/o-ring seal.

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127

Let’s switch to what NASA uses!!!

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It is good for low temps, it’s actually one of the best out there but it’s retention is weaker and it can’t retain formation for long and it sucks with compression and vacuum for long periods of time making them disposable after so many runs.

Though, you’re right they’re not as good as FKM for longer uses.

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ORB fittings are just not a great solution here. They will only make a seal if the o-ring retains some resiliency. PTFE doesn’t really have any to begin with. It would have been much better if they had used compression there instead of threads…

But is that the air port? If so then the leak is internal and no liquid should ever even reach that point.

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No this is one of the pumps two outlet ports.

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Like others said, ptfe is not the move here. They make a number of gaskets that are used for very cold hydrocarbons but they are usually custom ordered and VERY expensive, at least in the industrial manufacturing space

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We got you… Gylon is rated +250c to -260c.

Costs about the same as viton.

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Sort of…

the triclamp version won’t solve the leak in question

However, from a materials standpoint it might be worth trying to track down the correct o-ring size in gylon.

Certainly an easier fix than re-engineering to remove the ORB fittings that are leaking

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