What is an oil bubbler (gas bubbler)? When is it required?

An oil bubbler (also called a gas bubbler) is a common piece of general laboratory glassware, which is part filled with oil and vented to the atmosphere.

Oil bubblers are generally used to prevent pressure build-up while maintaining an inert atmosphere inside a vessel.  Gas passes (bubbles) out through the bubbler, but air does not pass back through the bubbler to the reaction.  The bubbler therefore acts as a one-way valve.  Oil bubblers also provide a way to view the rate of gas flow.

Radleys tend to sell oil bubblers for use with jacketed lab reactors (such as Reactor-Ready) for work under nitrogen etc., as it is important not to pressurise glassware (as described in the separate FAQ entry on jacketed lab reactors and pressure).

You may find bubblers in the lab set up with Schlenk lines (vacuum-gas manifolds).

Our standard part numbers are as follows; alternative joint sizes (and designs) are available:

  • RR139051: Oil Bubbler Type 1 B24 + GL14 + fittings
  • RR139314: Oil Bubbler Type 1 B29 + GL14 + fittings
When filling an oil bubbler, the oil fill level should be above the bottom of the inner dip tube, but below the side arm.
oil bubbler