QWORK Glass Vacuum Filtration Set, 1000 mL Flask & 300 mL Funnel – 10 μm Pore for Lab Liquid Clarification, Sample Prep & Solvent Filtration

Works perfect. Wish I could buy the components separately, though.

This is a review for the QWORK 1000ml vacuum filtration assembly. It arrived packed well in molded styrofoam which can also be used for storage. It does not come with a vacuum pump or aspirator. There are six components: the beaker, the neck attachment with vacuum port, the screw on check valve with plastic hose barb, the funnel, the stainless steel lid, and the clamp. You will need vacuum grease for the ground glass joints which connect the beaker neck with the vacuum port. If you do not use grease there is a potential for the connection to "freeze" and it will not be able to be unstuck, resulting in one piece having to be broken off. A review complained about this happening to theirs, so this is not an idle worry. There is specific vacuum grease (from Dupont, I think) but an inert, food safe silicone grease can be used in its place. I use "Super Lube Silicone Dielectric Grease (Food Grade) Part No. 91003" which is available on amazon, is cheap, and can be used for all sorts of other things as well. You want to apply two very thin lines on either side of the beaker neck, seat the other piece, and rotate until the grease coats the two joints uniformly. It can be wiped off before cleaning. The neck piece with the vacuum port contains a glass frit filter which can be used without filter paper if you want. However I recommend getting filter paper since it makes cleaning much easier, and you can filter finer particulates. I use the "Whatman 1001-055 Qualitative Filter Papers; 5.5 cm Diameter; Pore Size, 11µ" and it works well. If you do not use the filters, DO NOT try to filter out carbon, either from charcoal or activated carbon or any other source. It will be caught in the frit and is almost impossible to clean out (strong caustic acids are required which cannot be purchased by consumers). Also, do not use it to filter any strong sodium hydroxide solutions (lye) since this eats glass and can change the pore size of the frit filter. I found that grease is not needed between the neck and the funnel if it is fitted correctly. You must be careful with how you handle the assembly. For instance, there is no lip on the beaker neck, so if you grasp the beaker by the neck and try to move it, it can slip through your grasp and fall. Having the rest of the assembly put together makes this tempting because it looks to be solid, but only grease is holding everything together between the beaker and the rest of the assembly, and if you try to pick it up from the neck it will all fall apart. Don't do it. If you want to retain the filtered matter from the funnel, it is not difficult if all of the solvent has been removed, since the particulate will be retained enough from compaction that removing the funnel will not make it immediately fall out. However if there is any solvent in the funnel you want to remove, you will have a hard time doing it without siphoning it out the top, or doing some quick acrobatics flipping everything over quickly. Unclamping the funnel from the neck with the vacuum port will result in liquids immediately spilling out from the bottom of the funnel, since any filter paper and the frit is in the neck part. The plastic barb screws onto the vacuum port and contains a check valve, so that nothing can flow backwards into the assembly. This will keep a vacuum as long as you don't remove it and there is enough solution in the funnel to keep out the atmosphere. For the vacuum, you do not need anything strong. Vacuum pumps do not move much volume since they push out gas via compression. High flow rate pumps are not ideal. I am using a small air pump for an aquarium, with a hole drilled into the inlet and a 1/4" hose barb glued in. The one I use is the "Tetra Whisper Easy to Use Air Pump for Aquariums (Non-UL)" (the size for 10 gallon sized aquariums). The glass components are thick walled and well made, and fit together perfectly. Overall, do not expect vacuum filtering to be fast, clean, or easy -- but it is definitely much better than gravity filtering and this assembly will do the job. I have not tried any others, but this seems to be a great pick if quality is desired but money is tight.

I regret buying it due to unavailability of replacement parts. It was the only filter apparatus I could find that takes 47mm membrane filters. After breaking the flask (it broke dropping it from ~1/4" onto the bench - I wonder if it was correctly annealed) it is pretty much useless, as flasks with 24/40 OUTER (=male) joint appear to be impossible to buy anywhere (the one flask QWORK offers has a wrong description).

Works well. Seals with a paper filter inside. Could use graduation marks.

This doesn't filter at all if you are trying to use a filter pad. Whatever liquid are trying to filter is just stuck in the upper chamber.

Product ordered on Jan 21 received in Canada on Jan 27, not bad at all for economy shipping. Product was very well packed, I appreciate that and arrived intact. The product seems to be of good quality, no manufacturing defects, ground joint is made right with no play (this is the most common spot for low quality product). Glass frit filter is flat, flashed when both parts are together, and smooth. All in one it is a good value for the money.

Resulta muy práctico, de buena calidad y eficiente para las funciones propias del equipo.

Generally well made and suitable for its purpose but the vacuum hose leaks slightly so for a slow filtration you can't turn the pump off. The flask bottom cracked off but I was heating it to melt solids stuck on the inside. Not with more heat than other borosilicate flasks and beakers tolerated though so it is partly the design can't handle warming/heating.