PTFE Key Stopcock Double Oblique Bore – Advanced Vacuum & Gas Switching

The SGC LABS® PTFE Key Stopcock Double Oblique Bore is a highly specialized 3-way valve designed for complex atmospheric control in synthetic chemistry. Unlike standard T-bore stopcocks, the double oblique design features two distinct, parallel diagonal bores drilled through the solid Teflon (PTFE) key. This unique internal geometry allows the user to cleanly switch a reaction flask between a vacuum source and an inert gas source (like Argon or Nitrogen) simply by rotating the plug 180 degrees, without ever exposing the system to room air or mixing the two main lines.

Designed for Dual-Bank Manifolds – Structural Advantages

When working with air-sensitive or moisture-sensitive compounds, reliable isolation and rapid line switching are mandatory. Our double oblique stopcock excels in these demanding environments:

• Complete Line Isolation: The dual diagonal channels ensure that the two parallel sidearms never interconnect with each other, strictly routing only one sidearm to the bottom outlet at a time.
• Grease-Free Vacuum Seals: High-vacuum applications traditionally require heavy silicone grease, which easily migrates into reaction flasks. The self-lubricating PTFE key provides a highly secure, dry seal that maintains vacuum integrity without chemical contamination.
• Eliminates Glass Freezing: Exposure to strong basic vapors or continuous high-vacuum pressure often causes glass plugs to seize permanently. PTFE ensures smooth rotation regardless of the operational conditions.
• Heavy-Duty Borosilicate Housing: Crafted from thick-walled Borosilicate Glass 3.3, the outer shell is highly resistant to both the physical torque of turning the stopcock and the thermal shock of sudden temperature changes.

Key Features

• Material (Shell): Heavy-wall Borosilicate Glass 3.3 – extreme chemical and thermal resistance
• Material (Plug): Pure grade PTFE (Teflon) – self-lubricating, non-stick, and chemically inert
• Bore Type: Double Oblique (two parallel diagonal channels)
• Common Bore Diameters: 2.0mm, 3.0mm, 4.0mm, and 6.0mm (designed for rapid pump-down times)
• Retention System: Threaded polypropylene locking nut with a constant-tension pressure washer
• Temperature Tolerance: Glass safe up to 500°C; PTFE plug stable up to 250°C
• Compliance: Precision ground to meet and exceed ISO 4785 / DIN 12541 standards

Double Oblique vs T-Bore Stopcocks

Applications

• Air-free synthesis and organometallic chemistry setups (Schlenk lines)
• Dual-bank vacuum and inert gas manifold systems
• Custom scientific glassware assemblies requiring strict line isolation
• High-purity academic research and industrial analytical laboratories

Why Choose SGC LABS®?

Due to its complex internal geometry, the double oblique stopcock requires masterful precision during manufacturing. At SGC LABS®, our automated grinding processes ensure an exact 1:10 taper fit, preventing any micro-leaks between the high-vacuum side and the positive-pressure gas side. Every assembled stopcock undergoes rigorous vacuum-leak testing at our state-of-the-art facility in Ambala, India. We have been the standard-bearers of laboratory glass precision since 2003.