Sciencemadness Discussion Board

Perkins triangle frustrations..

Funkerman23 - 8-9-2015 at 22:38

This isn't the first time I've gone round and round on this but why are they so bloody elusive? For the unaware, this is an adapter for vacuum distillations that allows you to change flasks without loosing vacuum. Has anyone here ever found one by luck or had a buddy at ace glass? I have yet to see any Chinese glassblowers make a copy either.. with the possible exception of one Canadian seller ( forgot the name ). I get that for most people the udder & flasks is preffered but still.. Anybody else out there look for one( or other apparently Obscure) adapter and have luck? Any tips on finding one without selling an arm & leg? Pardon me if this isn't to standards but this is kicking my backside. I am aware the Quick-fit ones are more common but between overseas shipping and leaking joint adapters it is less than appealing( that and the cost is still 300 plus as of last sighting).
agghh!!

byko3y - 8-9-2015 at 23:32

I have no idea why somebody would need this adapter. For most cases spider adapter does the job.

Marvin - 9-9-2015 at 04:35

Quote: Originally posted by Funkerman23  
I am aware the Quick-fit ones are more common...


I don't understand what you are asking for.

http://www.gblaboratoryequipment.co.uk/ra633-intermediate-pe...

This looks like a much better version to me.

Part of your problem may be that the "Perkin triangle" looks to be a British term.

Dr.Bob - 9-9-2015 at 04:53

Are you looking for one in 24/40? I may still have one somewhere. I used to have several similar ones to that. I'll take a look, and I can set a reasonable price.

macckone - 9-9-2015 at 09:42

This can be replicated with a three way valve, A seperatory or
addition funnel, and a couple of vacuum adapters (one 105 degree
and one straight). Set up the funnel as the collection flask. With
the 105 degree adapter as normal for a vacuum distillation.
Then place the straight through vacuum adapter at the bottom of
the funnel.Then attach the three way valve to your vacuum
manifold and your inert gas source. The trick is to slowly open the
three way valve to the vacuum manifold so you don't lose
suction. The only thing special needed is a seperatory or addition
funnel with the correct fittings on top and bottom. A pressure
equalizing addition funnel is not useful for this as you don't want
the pressure equal.

ps. They are probably not made much because they can be
constructed from readily available parts that most labs can
use for multiple purposes. For large scale production lab glass
wouldn't be used.

[Edited on 9-9-2015 by macckone]

Funkerman23 - 9-9-2015 at 16:20

Quote: Originally posted by Dr.Bob  
Are you looking for one in 24/40? I may still have one somewhere. I used to have several similar ones to that. I'll take a look, and I can set a reasonable price.
in 24 /40 yes. I don't know what kind of chemist has such the array you do but it might be worth looking into degree-wise but I digress.

As to why need one: well in truth I'd need a spider adapter as well, given have neither.. but as too many here can attest; sometimes you have to make your own reagents if you want to experiment.

I also just collect labglass. Its a strange aside to a chemistry career but well made glass is a sight to behold. Given all the vices of the world, collecting glassware should be too worrisome.

j_sum1 - 9-9-2015 at 17:01

Ahhh. For the glassware collection.
I have no need for one of these and would not really know what to do with it if I had one. But I have to admit that it looks really cool!
ra6-11-intermediate-perkin-triangle-quickfit-laboratory-glass-lab-14-23-ns14-b14-1220-p.jpg - 16kB

ra6-33-intermediate-perkin-triangle-quickfit-laboratory-glass-lab-24-29-ns24-b24-1222-p.jpg - 19kB

Funkerman23 - 12-9-2015 at 17:00

Quote: Originally posted by macckone  
This can be replicated with a three way valve, A seperatory or
addition funnel, and a couple of vacuum adapters (one 105 degree
and one straight). Set up the funnel as the collection flask. With
the 105 degree adapter as normal for a vacuum distillation.
Then place the straight through vacuum adapter at the bottom of
the funnel.Then attach the three way valve to your vacuum
manifold and your inert gas source. The trick is to slowly open the
three way valve to the vacuum manifold so you don't lose
suction. The only thing special needed is a seperatory or addition
funnel with the correct fittings on top and bottom. A pressure
equalizing addition funnel is not useful for this as you don't want
the pressure equal.

ps. They are probably not made much because they can be
constructed from readily available parts that most labs can
use for multiple purposes. For large scale production lab glass
wouldn't be used.

[Edited on 9-9-2015 by macckone]
Please pardon my asking but have you tried this setup yourself and had it work?( I am genuinely asking, not trying to be rude)Was the vacuum loss manageable? A few 3 way stopcocks and some tubing is a lot cheaper seeing as I only lack the 3 way valve. Thanks to another seller here, J2xP( who is has disappeared sadly) I have a full 24/40 corning kit so I have a non equilibrium funnel already. He and Dr bob are saints to this little forum.

macckone - 13-9-2015 at 10:58

Yes it works. The trick is that some vacuum will be lost when switching over the three way valve. If you do it slowly it isn't a problem. Three way valves are cheap and depending on your reactants may not need glass and teflon. Glass and teflon are $40 on ebay but others are $10.

macckone - 13-9-2015 at 14:55

Ps if vacuum loss is a problem then one additional three way valve give exactly the same functionality as the Perkins triangle.

[Edited on 13-9-2015 by macckone]

careysub - 13-9-2015 at 18:37

Quote: Originally posted by macckone  
Yes it works. The trick is that some vacuum will be lost when switching over the three way valve. If you do it slowly it isn't a problem. Three way valves are cheap and depending on your reactants may not need glass and teflon. Glass and teflon are $40 on ebay but others are $10.


Is this what you are thinking of (the only glass three-way valve I find on eBay):
http://www.ebay.com/itm/GL98-PYREX-No-7382-GLASS-w-PTFE-PLUG...

I find no three way ST glass valves on eBay or on the Laboy site.

macckone - 15-9-2015 at 09:48

Yes that is what I was thinking of.
The $10 ones are pvc and for water.
You can probably find ones of other materials
like LDPE, HDPE or PP.
PVC will work for a lot of things but
not for a large number of solvents.

Here is another one on ebay that costs less:

http://www.ebay.com/itm/Kontes-T-Bore-Tee-Three-Arm-with-Gla...

Here is another model:
http://www.finemech.com/mm5/4.24/normag_datasheets/4.5.jpg

Not sure of cost or availability on that one.

Here are some manifolds that are not cheap:

http://unitedglasstech.com/Manifolds.htm

The three place is quite useful but I don't currently have one.

Another source without prices:

https://www.wilmad-labglass.com/ProductList.aspx?t=1153

I don't know if wilmad sells to individuals, but unitedglasstech does.

macckone - 15-9-2015 at 09:51

Here is a cheaper one, but it is 2mm

http://www.ebay.com/itm/2mm-KIMAX-T-Bore-Glass-Stopcock-NOS-...