Can I use a Carousel 6 Plus or Carousel 12 Plus with corrosive chemicals? How can I reflux effectively?

The Carousel 6 Plus and Carousel 12 Plus, like other Radleys equipment, have been designed to have good general chemical resistance.

However, it is not possible for any equipment to be completely unaffected by all possible reaction conditions.  It is not feasible for our R&D Laboratory to test equipment with every possible chemical/concentration/application, so unfortunately we are unable to make guarantees regarding specific chemicals.

We can provide information on the materials of the Carousels and give general advice, so that you can make an informed decision and reduce the risk/rate of any corrosion.

The main materials that the chemicals in the flasks could come into contact with during use are:

  • Carousel 6 Plus flask and reflux tube, or Carousel 12 Plus tube – borosilicate glass 3.3
  • White cap – PTFE
  • Septa of any sidearms (Carousel 6 Plus) – PTFE face
  • O-rings within the PTFE caps and on the gas outlets of the reflux head (that the caps fit onto) – nitrile as standard, but also available in Viton
  • Septa (Suba-Seals) in the caps – silicone as standard, also available in Viton
  • Gas outlets of the reflux head (vapours should preferably not reach this far) – stainless steel 316
  • Reflux head (vapours shouldn’t reach this far) – main material aluminium, with silicone gasket

You should consider the compatibility of these materials with the chemicals you want to use. If necessary, you can refer to chemical resistance tables online.

If the alternative materials we offer are more compatible with your chemistry than the standard ones (the ones that come with the Carousel), you should purchase the alternatives for improved lifespan/performance of the parts in question.

Please regularly check the condition of all the parts in the Carousel system, particularly the common consumables such as O-rings. If any part is damaged, it should be replaced as soon as possible to ensure there are no significant issues.

It is important to use your Carousel according to our recommendations below, to reduce the risk/rate of any damage. The aim is for chemical vapours to be effectively condensed in the reflux tubes or Carousel 12 Plus tubes, by the cooling of the reflux head. We advise:

  • Always use a suitable cooling water supply, flowing through the reflux head. Ensure the temperature is appropriate, considering the boiling point of the chemicals being used. Use a chiller if needed.
  • Do not overheat. If you heat high above the boiling point, you could generate too much vapour for the reflux head to be able to condense. (There is no benefit to the chemistry in overheating; the chemistry cannot get any hotter than the boiling point of the solvent, no matter how high the temperature is set to.)
  • Do not overfill the flasks/tubes, as this too could lead to too much vapour being produced.
  • For the Carousel 6 Plus, ensure the reflux inserts (the metal pieces you take out the reflux head to put the flasks in) are all inserted and properly in place.
  • Use an inert gas (typically a nitrogen blanket) if possible, not exceeding 1 psi (slight positive pressure).  This would help suppress the chemical vapours.
  • In all cases, particular care should be taken if the solvent has a low boiling point, or is corrosive.
  • You may need to experiment to work out the optimal conditions for a particular application.
  • Wipe off any spillages on the Carousel as soon as possible.

In addition to this advice, we recommend that Carousel units are always operated within a fume hood, away from any potential sources of chemical vapours (such as open bottles of acid), to protect the outer surfaces of the Carousel from any damage from the surrounding environment.