Get a one way valve there very cheap. I use to have a “genius” who worked for me do it all the time. Bhogart sells kf25 ones
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How will this help with the corrosion on the nut?
Its to stop oil from getting in your oven. I have no idea about or how your getting corrosion, if its not effecting your vacuum depth who cares about it
I have a Y connection so I can run 2 ovens to one pump as necessary. As for the corrosion, it hasnt affected the pump performance yet, but I just want to keep it that way. How frequently do you do pump oil changes?
I dont eun ovens and assuming theres not tons of alcohol ( if your doing etho products) i use to change mine about once every week or two. I only do distilation now and i change my oil every 2 second passes unless i notice i higher vac level than usual. I also use a roughing pump that take the brunt of all terps etc. get the baffle from Bhogart or im wire you can find one cheaper if tou look then just run a Y after the baffle. Just noticed you already run a Y
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so long as you’re not using a lot of ethanol, there is no absolute need for a cold trap.
ie: you’re not winterizing with ethanol & you’re not making EHO
however, see “holy water”, which was stuff that didn’t go into the pump because of a cold trap.
the “terpshine” from the cold -trap when purging winterized BHO is also a joy 
Happened to me.
You have to close the vacuum inlet valve on the oven before you shut off the vac pump. Have to.
If you don’t, suddenly that large oven space full of vacuum pulls against the pump when the pump suddenly stops pulling against it, and whatever is in the pump gets sucked backwards into the oven.
I was more fortunate, I use one of those cheap blue and white Chinese water aspirators (we call them R2-D2s) so I only got water in the oven. We are ethanol-only so we don’t have to oven quite as hard as the butane bois so no need for a fancy vac pump. The water catches the few volatiles.
If the pump fails its cheap to get another one from my lifelong new eternal best friend LanPhanDan. They are actually surprisingly robust. We beat the hell out of them like a rented droid and they take it.
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Not needing as good a vacuum as the butane bois for etoh makes no sense to me. When I purge etoh laden absolutes I need a harder aka higher vac to achieve lower purge temps then I would with hydrocarbon oleoresins… ime
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Yes I am making EHO. There is about 5-10% ethanol left in the oil solution when put into the oven. So If I’m putting 1000g into the oven there could be approx 100g of Ethanol flowing into the pump.
What micron/mtorr and temp do you pull your EHO to?
a rotoray vane pump will not appreciate that. certainly not long term.
I’d say your consultant was wrong. unless you’re running a diaphragm pump or an aspirator, you should have a cold trap on your oven when processing EHO.
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Isnt the rotary vane just going to pull some of the solvent out of the cold trap anyway? Even if I do frequent oil changes (1x-2x a week) is it still a problem to not use a cold trap?
it’s your pump.
Meaning it’s just going to kill the pump overtime?
I would blame ethanol ingestion for the premature failure of at least two of the rotary vane pumps that have died on my watch.
They were cheap, and I did EXPLICTLY list destroying two of them on my one of my early equipment lists. So I don’t feel particularly guilty about it. Ymmv
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I’m using a “Pro Series 11.3CFM Corrosion Resistant Two Stage Vacuum Pump” from best value vac. Would you consider this a “cheap” pump?
Ive kilt a few nice pumps from getting em too drunk , expensive mistake.
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At $2200? No. I would spend another $200 for a dry ice based cold trap. Or $1000 for a mechanical one off eBay.
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Hello I have a dumb question, I run Edwards 30 pumps, so what you explained here makes since, so my question is , can that same thing happen with these types of pumps I’m running, thus contaminating products I’m trying to purge of ethanol in the oven(AI)
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Yes. If you turn off the pump while the oven is under vacuum, and all the valves are open, vacuum oil can be pulled into the chamber.
Be disciplined about your order of operation. Remember to keep your pump turned on or isolated from vacuum.
I’ve walked hundreds of guys through this over the phone. If you’re still not sure, dm. I’m sure once we talk it through, it will make sense. Once you get it, you won’t make that mistake.
Here’s a video, start at minute 3
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