Dropping Funnel Pressure Equalising, Jointed

This pressure-equalising dropping funnel is jointed and graduated, and is lab glassware for adding liquids in a controlled way to a closed system, such as under vacuum or inert gas. A side tube balances the pressure inside, so reagents flow smoothly without you having to remove the stopper.

Key Components

• Pressure-equalising arm: A narrow glass tube connecting the top of the funnel to the stem below the stopcock to keep the pressure constant.
• Graduations: High-visibility markings (usually white enamel) for measuring exactly how much liquid you add.
• Jointed connections: Standard taper ground glass joints:
  • Top (socket): For a stopper or condenser.
  • Bottom (cone): Fits securely into a reaction flask.
• Material: Borosilicate 3.3 glass, with good thermal shock resistance and chemical durability.
• Sizes: Select the capacity and joint size from the drop-down.

Tips for Use

• Inert environments: Essential for air-sensitive reagents where the system has to stay sealed.
• Stopcock choice: PTFE stopcocks are preferred for high-purity or corrosive work, as they don't need grease and won't seize.
• Cleaning: If you use a glass stopcock, grease it lightly so it doesn't jam.