Timeline for Order of internal pressure resistance to expect from laboratory glassware?
Current License: CC BY-SA 4.0
17 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 6, 2019 at 7:44 | history | edited | Hans | CC BY-SA 4.0 |
edited title
|
| Jul 30, 2019 at 3:04 | comment | added | Hans | @matt_black Thanks! I had actually been wondering whether a cylinder or a spherical container would take most pressure. Somewhat instinctively, it was clear to me that both would hold more pressure than an erlenmeyer but I failed to rationalise about the angle. | |
| Jul 29, 2019 at 23:53 | comment | added | matt_black | Oh, and a good generalisation on shape is that the more pressure the "rounder" the shape needs to be. Vessels with flat portions or sharp edges will be very poor under pressure. | |
| Jul 29, 2019 at 23:51 | comment | added | matt_black | Most chemists who need to do reactions at pressure use specialist vessels designed to do so not standard glassware which very much isn't designed to do so. Large volume pressure vessels will usually be made of metal (which is far better under pressure than glass). Or, perhaps, internally glass coated metal vessels). There are some specialist thick-walled glass vessels designed to cope with some modest pressure, but they will usually be fitted with specialist pressure seals: standard glass joints don't work under internal pressure. | |
| Jul 28, 2019 at 22:53 | vote | accept | Hans | ||
| Jul 28, 2019 at 21:29 | answer | added | DrMoishe Pippik | timeline score: 2 | |
| Jul 28, 2019 at 15:28 | comment | added | Ivan Neretin | Yes I thought of assemblies that disconnect without breaking. Metal clips are not strong enough to counter that. If they were made stronger, they themselves would break the glass when without pressure. | |
| Jul 28, 2019 at 2:06 | comment | added | Hans | *put the flask at the bottom | |
| Jul 27, 2019 at 22:29 | comment | added | Hans | In the worst case I could but the flask at the bottom of a swimming pool, with 5 meters depth that would allow me to put 0.5 bar of additional pressure inside, all things kept equal. I'd just have to figure out the +5 meter long glass joints out of it... :S Maybe not worth the effort for just +0.5 bar. | |
| Jul 27, 2019 at 22:18 | comment | added | Jon Custer | I am pretty sure you won’t find anyone stating their glassware will take anything greater than 1atm. That puts it into pressure vessel territory. | |
| Jul 27, 2019 at 22:17 | comment | added | Hans | Or do you mean the joints not breaking but dissociating (as the vessel dissociating from the piece of glassware connected to one if its joints without either breaking)? I've seen metal clips available, if they are any better at keeping joints together? | |
| Jul 27, 2019 at 22:14 | comment | added | Hans | What level of internal pressure (in Bars) would you think each of my two flasks could withstand with less than 10% risk of breaking at those joints? 10% is high but I'm fine operating with 1/10 chance it will break, as long as it's not much more than that. If it breaks at the joint and the flask is surrounded by a glass cylinder at worst the joints and connection will fly/jump upwards. It would be better than the body breaking as there's less chance I'd have to deal with a liquid mess. I may even be able to salvage the solution and filter out possible glass shards. | |
| Jul 27, 2019 at 21:54 | comment | added | Ivan Neretin | No, I mean the part where two vessels meet. When you have vacuum inside, they are pressed together with great force, which is good. But internal pressure seeks to tear them apart. | |
| Jul 27, 2019 at 21:47 | comment | added | Hans | @IvanNeretin That's interesting. Instinctively I would have worried the least about the joints as they seem to be the most resistant parts of the vessels. Do you mean the part where they connect to the body of the vessel? | |
| Jul 27, 2019 at 21:46 | history | edited | Hans | CC BY-SA 4.0 |
added 27 characters in body; edited title
|
| Jul 27, 2019 at 21:35 | comment | added | Ivan Neretin | Glass in general is relatively bad at withstanding internal pressure, and glass joints in particular are even worse. | |
| Jul 27, 2019 at 20:57 | history | asked | Hans | CC BY-SA 4.0 |