PTFE Key Stopcock for Separatory Funnel – Contamination-Free Chemical Extraction
The SGC LABS® PTFE Key Stopcock for Separatory Funnel is an essential upgrade for analytical and organic chemistry laboratories. Liquid-liquid extraction often involves aggressive organic solvents like dichloromethane, chloroform, or diethyl ether. Traditional glass stopcocks require silicone or hydrocarbon grease, which easily dissolves into these solvents, contaminating your chemical layers and ruining experimental yields. Our grease-free Teflon (PTFE) key stopcock solves this issue entirely, keeping your extractions pure and clean.

Engineered for Liquid Separation – Practical Design Advantages
When separating distinct liquid phases, a smooth-turning, reliable valve is critical. Our separatory funnel stopcock offers superior performance features:

100% Grease-Free Extraction: Protects organic layers from grease artifacts, ensuring clean NMR, GC-MS, and analytical results.
Excellent Phase Control: Highly responsive straight bore channel allows you to shut off the flow exactly at the interface line between the two liquids.
High Chemical Inertness: The solid PTFE plug withstands continuous exposure to strong acids, bases, and highly active organic solvents.
Anti-Locking Barrel Design: Unlike glass plugs that freeze up tightly when exposed to alkaline aqueous phases, the PTFE plug always turns easily and smoothly.
Adjustable Tension Nut: Features a robust threaded retaining system with a washer to fine-tune the seating tension, eliminating drip leaks during vigorous shaking.

Key Features

Material (Body): Heavy-wall Borosilicate Glass 3.3 – highly resistant to mechanical impact and chemical stress
Material (Plug): Premium grade PTFE (Teflon) – self-lubricating and completely inert
Bore Path: Straight bore configuration for a direct, high-flow drainage path
Available Bore Diameters: 2.0mm, 3.0mm, 4.0mm, and 6.0mm (to match funnels from 50ml up to 5000ml)
Sealing Kit: Threaded polypropylene locking nut, pressure washer, and rubber O-ring seal
Autoclave Compatibility: Fully sterilizable and chemical-wash-safe up to 121°C
Standardization: Tailored to conform to ISO 4800 / DIN 12424 separatory funnel specifications

PTFE vs Glass Stopcocks in Separatory Funnels

Extraction Challenges
PTFE Key Funnel Stopcock
Traditional Glass Key Stopcock

Solvent Interaction
Completely inert; does not dissolve or react
Solvents leach grease into your chemical samples

Vigorous Shaking Seal
Securely tightened via nut; no pressure leaks
Grease can thin out under pressure, causing leaks

Alkali Phase Reaction
No effect; resists base-washing steps easily
Bases (like NaOH washes) quickly cause glass-to-glass freezing

Post-Extraction Cleaning
Quick rinse with acetone; ready for reuse
Tedious process to completely strip out old grease residue

Applications

Perfect replacement stopcock for Squibb, pear-shaped, and cylindrical separatory funnels
Liquid-liquid partition extractions in academic, research, and organic synthesis labs
Essential component for environmental testing labs separating oil/water matrices
Custom scientific glass blowing and product recovery manifold systems

Why Choose SGC LABS®?
SGC LABS® separatory funnel stopcocks are ground on automated CNC machines to a perfect 1:10 standard taper. This precise geometry prevents any micro-channel creation, ensuring the plug maintains a liquid-tight seal even when volatile organic solvents build up internal pressure during mixing. Every piece is pressure-tested at our state-of-the-art facility in Ambala, India. SGC LABS® has been the trusted name in laboratory glassware engineering since 2003.