|WikiProject Chemistry||(Rated C-class, Low-importance)|
|WikiProject Glass||(Rated C-class, Low-importance)|
I would certainly question this. Volumetric flasks, in my experience of A-level chemistry, university and having tens of them myself, says they do use ground sockets. The same is true of sep funnels, as it is common for people to swirl the funnel upside down (so the liquid would pour out if it weren't ground well); I usually don't do this myself, given the risk of it ending up on the floor, and instead vent through the cap. And again, for volumetric flasks, when diluting to make a stock solution, they need inverting multiple times to homogenise the solution. Storage bottles, very few ever use ground tapers, only older style bench bottles of things like sulphuric (we still used such bottles at A-level chemistry with a dripper pipette in the cap for sulphuric, I expect so that the students didn't have to pour from the larger bottles). Glass tapers are prone to jamming when left in contact with numerous materials for extended periods of time. A large percentage of them use GL caps. As far as I'm aware ALL of the Schott Duran style borosillicate bottles use GL caps; like GL45. As well as the Winchesters I get things in from the suppliers. The GL cap allows a pump pipette to be screwed onto the top to dispense the reagent without having to pour and measure it as separate operations. Some of these pipettes are mechanical and preset (e.g. 1ml), some are variable, the most expensive are variable digital models.
I didn't add any of this, but it is partially correct. I have a stack of volumetric flasks in front of me right now. Some of the joint sizes, for example, are 16/16, 14/15 and 10/13. I tried a B14/23 stopper (the kind normally used on RBF's) in one and it does fit, but the stopper sticks out on the inside a little too far (it's a few mm too long). So they must be the same taper, but different lengths. There are also sizes for volumetric flasks that are not available (at all) from the B's, like C16; for which there is no B16. All of the female joints on volumetric flasks are shorter than the normal B sizes. I have no idea why. Maybe it's a conspiracy to make us buy more stoppers. Or something to do with the tolerances bands or not mixing them up (if that was true, they should have made all volumetric flasks 'odd' sizes compared to normal B's). I think this may also apply for taps on things like funnels, a B14 will not fit in the tap I have here even though they appear to be the same size (the taper is wrong).
Generally, when I've seen stoppers for volumetric flasks, they're just given the name C16 etc. But this is akin to calling B24/29 'B24' since the rest of it rarely matters. I use both US and UK glass, and I've never had a problem fitting the two together despite the different lengths.
US glass tapers are not universally longer. B14/20 from the US is shorter than the UK standard, B14/23; but the tapers are identical and they fit together. -- Preceding unsigned comment added by 22.214.171.124 (talk) 15:14, 28 June 2011 (UTC)
Anyone ever heard of Quickfit glass joints? --Alf 07:46, 9 January 2007 (UTC)
Is there anyone familiar with this subject? I failed to properly understand the difference between US and ISO standard taper. Are they both standard taper systems using xx/yy notation to denote diameter and length in mm of the joints? Are ISO 29/42 and US 29/42 identical? --Alf 07:50, 9 January 2007 (UTC)
Yes, they do use the same system of xx/yy for diameter and length. They also use the same taper. However there is no such thing as an ISO 29/42 (at least none that I have found). Instead it is 29/32. This is pretty much just a shorter version. They will be compatible, so you can put a US cone into a ISO socket or vice versa, with one exception, if you are using a US cone (42 mm long) in a ISO socket (32mm long) and there isn't enough room after the join to fit the remaining length of the socket. With the glassware I have dealt with I am yet to have this problem.Black.jeff (talk) 00:32, 4 September 2015 (UTC)
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