Buchner Flask

Buchner Flask

When you're filtering precipitates or collecting crystals, waiting for gravity filtration feels like watching paint dry. Buchner flasks solve this by connecting vacuum pressure directly to your filtration setup, pulling liquid through in seconds instead of minutes. The flat bottom keeps them stable on benchtops while that characteristic side arm does the real work.

Vacuum Filtration Excellence Using Buchner Flasks

The side-arm design transforms ordinary filtration into a rapid process by creating negative pressure below your filter paper. While standard Funnels rely on gravity alone, pairing a Buchner funnel with this flask cuts filtration time by 80-90% for most applications. You'll appreciate this speed difference when processing multiple samples or working with fine precipitates that would clog gravity systems.

Side-Arm Construction for Vacuum Connection

That angled tube jutting from the neck isn't just decorative - it's your vacuum interface. Connect it to your house vacuum or aspirator using thick-walled tubing that won't collapse under pressure. The connection point is reinforced because this is where stress concentrates during operation. Unlike Separatory Funnel or Funnel Separatory pear shape designs meant for liquid-liquid extraction, Buchner flasks handle the mechanical stress of sustained vacuum without imploding. Standard ground glass joints on larger models (500ml+) accept Hollowed glass stoppers when you need to seal the flask after filtration.

Capacity Options for Various Sample Volumes

• 125-250ml: Microscale work, single analytical samples
• 500-1000ml: Standard prep chemistry, most undergraduate labs
• 2000ml: Bulk crystallization, industrial QC testing

Match your flask size to funnel diameter - a 500ml flask pairs with 90mm funnels, while 1000ml units accommodate 120mm versions. Oversizing wastes solvent during washing steps; undersizing risks overflow.

Thick-Walled Design for Pressure Safety

Borosilicate walls measure 3-4mm thick compared to 1-2mm on regular flasks. This prevents catastrophic implosion when you're pulling 25-28 inches of mercury vacuum. Always inspect for star cracks around the side arm before use - that's where failures start. The flat bottom distributes pressure evenly, unlike round-bottom flasks that concentrate stress at the curve. For hot filtration above 80°C, the thermal shock resistance of borosilicate prevents cracking that would occur with soda-lime glass.