Draeger
Hazard to Others
Posts: 185
Registered: 31-1-2020
Location: North-Rhine Westfalia, Germany
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Mood: Slowly getting ready for new projects
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Getting loose PTFE stopcocks for addition funnel?
I have an addition funnel laying around, and I was wondering where I could get a Teflon stopcock? I really don't like the glass stopcock, and had I
known better I wouldn't have bought it. I tried to find Teflon stopcocks, but I couldn't find any except from companies like sigma or kimble chase,
which I can't buy from, and I want to avoid just buying a new addition funnel if I can.
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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Dr.Bob
International Hazard
Posts: 2753
Registered: 26-1-2011
Location: USA - NC
Member Is Offline
Mood: Mildly disgruntled scientist
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Was the stopcock originally glass? Glass stopcocks are made in one taper, and most PTFE ones are a different taper, so they are not interchangable.
I have seen a few odd sized PTFE ones, and a few companies may have made PTFE ones that fit into glass stopcock joints, but they are very hard to
find and rare. Glass ones come a few standard sizes, like #2 (typically found on 30 up to 500 ml sep funnels) and #4 (typically found on 500 ml and
larger sep funnels) but there are smaller and larger ones out there. Teflon ones come in similar sizes, but are a different angle, with a 2, 4, and
6 size, but not the same as the glass ones. These are all the simple straight bore ones, when you get to three way or vacuum stopcocks, there are
many more "standards", so it is very hard to match them.
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SWIM
National Hazard
Posts: 970
Registered: 3-9-2017
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I've got a few spares.
Not sure about sizes, is yours marked somehow?
EDIT: I don't know the pedigree on all of these, but I believe some have different taper angles than the others.
Guess I ought to check on that.
[Edited on 5-5-2020 by SWIM]
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Draeger
Hazard to Others
Posts: 185
Registered: 31-1-2020
Location: North-Rhine Westfalia, Germany
Member Is Offline
Mood: Slowly getting ready for new projects
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Quote: Originally posted by SWIM  | I've got a few spares.
Not sure about sizes, is yours marked somehow?
EDIT: I don't know the pedigree on all of these, but I believe some have different taper angles than the others.
Guess I ought to check on that.
[Edited on 5-5-2020 by SWIM] |
The only markings I found is on the top of the addition funnel and says "18.8", along with a symbol which is a sort of shield shape with an uppercase
"K" in it. The other marking just says how much fits into it.
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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Dr.Bob
International Hazard
Posts: 2753
Registered: 26-1-2011
Location: USA - NC
Member Is Offline
Mood: Mildly disgruntled scientist
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On SWIM's photo, the orange ones are Pyrex brand, they are standard PTFE taper, I have never seen one that is not. The blue ones are the same, but I
think maybe Kimex or Kimble brand. The yellow ones are maybe Kontes, they might be a differnet taper, as they oriuginally has a different one, but
eventually changed to be standard, I believe. The red might be Ace, and they also may have had some that were diffenent, but most seem standard now.
BTW, Chemglass ones are green, and are all standard as far as I can tell.
SWIM, if you are in the US, I would be interested in getting a few of the yellow or red ones, as I am short on those, but have scads of the orange and
blue, much like you do. I have a few sep funnels and addition funnels that need stopcocks that are NOT standard taper, and might fit your stopcocks.
I would be happy to pay or swap for them, if they are the non-standard ones.
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Draeger
Hazard to Others
Posts: 185
Registered: 31-1-2020
Location: North-Rhine Westfalia, Germany
Member Is Offline
Mood: Slowly getting ready for new projects
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| Quote: Originally posted by Dr.Bob | | Was the stopcock originally glass? Glass stopcocks are made in one taper, and most PTFE ones are a different taper, so they are not interchangable.
I have seen a few odd sized PTFE ones, and a few companies may have made PTFE ones that fit into glass stopcock joints, but they are very hard to
find and rare. Glass ones come a few standard sizes, like #2 (typically found on 30 up to 500 ml sep funnels) and #4 (typically found on 500 ml and
larger sep funnels) but there are smaller and larger ones out there. Teflon ones come in similar sizes, but are a different angle, with a 2, 4, and
6 size, but not the same as the glass ones. These are all the simple straight bore ones, when you get to three way or vacuum stopcocks, there are
many more "standards", so it is very hard to match them. |
Oh. Yeah, it was originally glass. Do you have any idea where I could maybe look for one of these special teflon stopcocks that fit into the glass
joints?
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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dawt
Hazard to Self
Posts: 74
Registered: 9-5-2016
Location: EU
Member Is Offline
Mood: fluorescent
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Since you're in Germany, I'd recommend measuring the length and the inner diameter of either side of the joint as accurately as you can, and sending
an email to these guys with the specs. I've only had good experiences with this company, they've been really helpful. 
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Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
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| Quote: Originally posted by dawt | | Since you're in Germany, I'd recommend measuring the length and the inner diameter of either side of the joint as accurately as you can, and sending
an email to these guys with the specs. I've only had good experiences with this company, they've been really helpful. |
lol, i was born in australia to german parents, learnt german first and ultimately my sensibilities align as more german than australian...albeit ive
lived here for my 47 years largely.
Anyway i just wanted to say.....how fucking typically german is that website...i love it.....if that company behaved as it does it here in australia
it would have failed years ago
thanks for sharing it....
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