Cylindrical funnels ISO4800, PTFE screw stopcock

ISO4800 Cylindrical Separatory Funnels with PTFE Valve Systems

Last month, a colleague spent three hours re-running an extraction because her old funnel's glass stopcock leaked dichloromethane all over the bench. She switched to these ISO4800-certified cylindrical funnels with PTFE screw stopcocks the next day and hasn't looked back. When you're separating organic phases at 2 AM before a conference deadline, equipment reliability isn't optional.

Borosilicate 3.3 glass construction handles everything from routine aqueous extractions to aggressive solvent systems. The PTFE screw stopcock eliminates the constant greasing and seizing issues that plague traditional glass valves, especially when working with non-polar solvents that strip away lubricants within minutes.

Advanced PTFE Screw Stopcock Performance

Traditional glass stopcocks require careful maintenance and regular re-greasing, but PTFE valves operate smoothly without any lubrication. The screw mechanism provides precise flow control that matters when you're collecting fractions or performing dropwise additions.

• No cross-contamination from stopcock grease migrating into your product
• Smooth operation even after months of storage without use
• Chemical resistance across pH ranges from concentrated acids to strong bases
• Temperature stability from -200°C to +250°C without degradation

Unlike Separatory Funnel models with standard glass valves, these PTFE systems work reliably with hexane, chloroform, and other solvents that dissolve typical lubricants.

Cylindrical Shape Advantages for Layer Observation

While Funnel Separatory pear shape designs taper for drainage, cylindrical bodies offer superior visibility during phase separation. The uniform diameter creates a consistent viewing plane that makes identifying emulsion layers significantly easier under laboratory lighting.

Running natural product extractions often produces stubborn emulsions at the interface. The straight walls let you monitor exactly where the boundary sits without the optical distortion that curved surfaces create. When paired with Hollowed glass stoppers at the top, you get complete seal integrity while maintaining pressure equalization during drainage.

Volume graduations etched directly onto the cylindrical surface remain accurate across the entire height, unlike conical shapes where meniscus reading becomes increasingly difficult near the narrow bottom.

Quality Assurance Through ISO4800 Certification

ISO4800 compliance means standardized dimensions that integrate seamlessly with other certified glassware. Ground glass joints match perfectly with Buchner Flask setups and standard Funnels for multi-stage extraction workflows.

• Controlled wall thickness prevents thermal stress fractures during temperature cycling
• Verified annealing processes eliminate internal strain points
• Dimensional consistency ensures reliable volume measurements
• Compatible with ring stands and support clamps following international specifications

Batch-to-batch consistency matters when validating analytical methods or running quality control protocols that demand reproducible results across different lab locations.