PTFE Key Stopcock for Burette – Precision Drop-by-Drop Titration
The SGC LABS® PTFE Key Stopcock for Burette is a crucial component for analytical chemistry labs demanding absolute precision during volumetric titrations. Traditional glass-key burettes require silicone grease, which can dissolve in organic solvents, clog the fine jet tip, or alter your titration readings. This modern Teflon (PTFE) key stopcock eliminates those problems entirely, providing a smooth, non-stick, and contamination-free fluid control mechanism.

Designed for Volumetric Accuracy – Key Structural Advantages
Our burette stopcock is specifically optimized to handle fine adjustments, which is essential when finding the exact endpoint of a chemical reaction:

Grease-Free Titration: No risk of chemical grease reacting with standard titrants like Sodium Hydroxide (NaOH) or Potassium Permanganate (KMnO4).
Micro-Drop Control: The straight bore internal alignment combined with a finely threaded locking nut gives the user the ability to release single micro-drops easily.
Zero Freezing: Alkaline solutions often cause glass plugs to lock up or “freeze” permanently. The non-stick nature of PTFE ensures the key always turns smoothly, even after prolonged storage.
Heavy-Duty Construction: The glass shell is made of thermal-shock-resistant Borosilicate Glass 3.3, featuring thick walls to withstand daily lab handling.

Key Features

Material (Shell): Borosilicate Glass 3.3 – highly resistant to chemical attack and thermal shock
Material (Key): Pure PTFE (Teflon) – self-lubricating, non-wetting, and inert
Application: Specifically designed for straight-tube glass burettes
Bore Size Options: 1.5mm, 2.0mm, and 2.5mm (optimized for precise drop delivery)
Assembly Components: Glass outer barrel, PTFE straight-bore plug, PP washer, and a threaded retention nut
Autoclave-Safe: Fully sterilizable up to 121°C
Standardization: Manufactured in accordance with ISO 385 / DIN 12700 burette specifications

PTFE vs Glass Burette Stopcocks – Performance Check

Titration Requirements
PTFE Key Burette Stopcock
Glass Key Burette Stopcock

Contamination Prevention
Excellent (100% Grease-free)
Poor (Grease can wash into the analyte)

Burette Tip Clogging
None – Flow path stays entirely clear
High (Excess grease often blocks the fine tip)

Alkali/Base Resistance
Highly Resistant (Does not freeze)
Poor (Strong bases fuse the glass parts together)

Flow Adjustment Fine-Tuning
Smooth, continuous turning feel
Can feel jerky or sticky if grease dries out

Applications

Replacement valve for standard 10ml, 25ml, 50ml, and 100ml glass burettes
Acid-base titration setups in educational, research, and analytical laboratories
Custom glass blowing and fabrication of specialized fluid-dispensing lines
Pharmaceutical testing and water quality checking systems

Why Choose SGC LABS®?
At SGC LABS®, our glass barrels are precision-honed on specialized machinery to ensure a seamless, uniform taper match with the PTFE key. This meticulous grinding prevents micro-leaks, ensuring that your expensive titrants do not drip during sensitive experiments. Every single burette stopcock is tested under strict quality control standards at our production plant in Ambala, India, ensuring reliable volumetric accuracy since 2003.