As a general rule, O-rings are consumables.  They should be regularly checked and replaced as required. It is not normal for these O-rings to need replacing very frequently, as the materials have been chosen for characteristics including chemical resistance, but their lifespan will depend on your application (which specific chemicals you use, and how you use the equipment). The O-rings in the white caps and on the gas outlets on the reflux head are nitrile as standard but are also available in Viton.  Please consult chemical compatibility tables to see which material is most suitable for your chemistry. Refluxing effectively should help minimise any damage to the O-rings; please see the instruction manual, and the FAQ entry ‘Can I use a Carousel 6 Plus or Carousel 12 Plus with corrosive chemicals?’, for further details. The part numbers are:

Gas outlet

  • RR91060: Nitrile O-Rings 4 mm Gas Outlet – Bottom (Pack of 50)
  • RR91061: Nitrile O-Rings 3 mm Gas Outlet – Top (Pack of 50)
  • RR91062: Viton O-Rings 4 mm Gas Outlet – Bottom (Pack of 50)
  • RR91063: Viton O-Rings 3 mm Gas Outlet – Top (Pack of 50)

Cap O-Ring

  • RR98060: O-Rings for Caps – Nitrile 24 mm (Pack of 100)
  • RR98160: O-Rings for Caps – Viton 24 mm (Pack of 100)
Replacement septa for the white caps and flask side arms, and O-rings for Rodaviss joints and wide neck couplings, are also available, with options of alternative materials in some cases.

I’ve broken a white or black connector (for water or gas) on my unit. Can I replace it?

The white (or black) plastic connectors for water or gas (we call them ‘quick connects’ or ‘quick release fittings’) on StarFish, Carousel 6 Plus and 12 Plus, GreenHouse Plus and GreenHouse Blowdown units are all available to purchase as spare parts.
White connectors
Please consult the relevant ‘quick connects’ guide (download from our website on the Technical Information Downloads page) or alternatively contact us so we can help you identify the correct part, including a photo if possible.
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.
We offer the following tubing for connecting the white fittings (quick connects) on the Carousel reflux/inerting head to your water or gas/vacuum supply:
  • RR99067: Tubing for Inert Gas or Reflux Cooling 2 Metres
Yes, you can use an azeotropic (Dean-Stark) flask with Tornado. Please note, it must be a Tornado azeotropic flask, as these have a wider neck than the standard azeotropic flasks to allow a stirrer shaft to fit through:
  • RR99939: 100 ml Tornado Azeotropic Reaction Flask (Pack of 3)
  • RR99938: 250 ml Tornado Azeotropic Reaction Flask (Pack of 3)
Furthermore, only the collapsible centrifugal stirrers will fit.  Anchor and propeller stirrers are too large to fit through the neck into the flask.
  • RR99240: Centrifugal PTFE Stirrer Paddle (Pack of 6)
  • RR99241: Centrifugal PTFE Stirrer Paddle (Pack of 1)
We offer PTFE insulating plates for the Carousel 6 Plus as an optional accessory.  The part number is RR96220. RR96220 is included if you purchase the Storm Work Station. The insulating plates provides a thermal barrier that both increases energy efficiency, maximising the performance of the Carousel 6 Plus, and provides a safety barrier, reducing the external temperature of the base, and so protecting the user from high temperatures.
The Carousel 6 Plus and Carousel 12 Plus reaction stations (and the older Classic versions), as well as the GreenHouse Plus Parallel Synthesiser (and Classic) and the GreenHouse Blowdown, all have a 135 mm diameter recess in the base for locating onto a hotplate. This means that they can be used with any stirring hotplate that has a 135 mm diameter top plate, such as the Radleys range of Carousel Stirring Hotplates. Standard Heidolph hotplates have a 145 mm top plate, and so are not compatible with this Radleys equipment.

What are aluminium flask inserts? When are they required?

In the Carousel 6 Plus (and Carousel 6 Classic), and StarFish (using the RR95130 MonoBlock for 5 x 250 ml Flasks), the well size is for 250 ml round bottom flasks. For smaller flasks, it is important to use aluminium reducing inserts to make the well smaller to enable good contact and so good heat transfer between the heated well and the flask.

Aluminium flask inserts

For StarFish, we sell these as singles, as customers are quite likely to be using PolyBlocks and/or different flask sizes at once.  The part numbers are:
  • RR95330: 150 ml Flask Insert (Pack of 1)
  • RR95335: 100 ml Flask Insert (Pack of 1)
  • RR95340: 50 ml Flask Insert (Pack of 1)
  • RR95345: 25 ml Flask Insert (Pack of 1)
  • RR95350: 10 ml Flask Insert (Pack of 1)
  • RR95355: 5 ml Flask Insert (Pack of 1)

Aluminium flask insert

For Carousel 6 Plus (and Classic), customers are more likely to be using the same flask volume in all 6 positions, and so we offer inserts in packs of 6:
  • RR99057: Aluminium Insert for 170 ml Reaction Flask (Pack of 6)
  • RR99058: Aluminium Insert for 100 ml Reaction Flask (Pack of 6)
  • RR99060: Aluminium Insert for 50 ml Reaction Flask (Pack of 6)
  • RR99140: Aluminium Insert for 25 ml Reaction Flask (Pack of 6)
  • RR99141: Aluminium Insert for 10 ml Reaction Flask (Pack of 6)
  • RR99142: Aluminium Insert for 5 ml Reaction Flask (Pack of 6)

How can I optimise my magnetic stirring?

To ensure the best possible stirring, we advise:
  • Use the stirring bar we recommend for the piece of equipment / glassware you are using.
  • You could alternatively test a range of stirring bars – we offer three stirring bar evaluation kits, each containing a selection of stirring bars of different sizes and shapes.
  • Standard stirring bars lose their magnetism with time and use, so try replacing old stirring bars.
  • Rare earth stirring bars contain stronger magnets than standard stirring bars, so are particularly useful for stirring relatively viscous samples.
  • If your sample is very viscous, it may be that magnetic stirring is not sufficient and you require overhead (mechanical) stirring instead.  Depending on your sample size and number, the Tornado module for the Carousel 6 may be appropriate for you, or you could use a single overhead stirrer motor with a stirring guide for a single flask in Heat-On or Cool-It.
For further details, please view the other FAQ entries on this topic – type ‘stirring bar’ in the search box.
After you’ve finished your synthesis reaction in the Carousel 6 Plus, you may wish to take the Carousel 6 Plus flask and connect it to a rotary evaporator (as the evaporating flask) to evaporate off the solvent.  This is when you would use a rotary evaporator adapter.

Carousel 6 rotary evaporator adapter

We offer three different rotary evaporator adapters (each in a pack of 2):
  • RR99045: Rotary Evaporator Adapters Rodaviss B29 Socket to B24 Cone
  • RR99046: Rotary Evaporator Adapters Ordinary B29 Socket to B24 Cone
  • RR99055: Rotary Evaporator Adapters USA 24/40 Socket to B24 Cone

Carousel 6 rotary evaporator adapter

You should avoid damage to the stainless steel gas outlets/inlets on the Carousel reflux head by ensuring you reflux effectively so that chemical vapours are retained in the flasks/tubes and do not pass up through the white PTFE caps to the gas outlets/inlets.  For guidance, please refer to the separate FAQs entry ‘Can I use a Carousel 6 Plus or Carousel 12 Plus with corrosive chemicals?’


Nonetheless, if the gas outlets do become corroded, they can be replaced:
  • RR91064: Spare Gas Outlet for Carousel 12 Plus + 6 Plus Including O-Rings (Pack of 6)

Gas outlet

The O-rings can also be purchased separately if required.  They are nitrile as standard, but are also available in Viton, so you can select which is most resistant to the chemicals you are using.
    • RR91060: Nitrile O-Rings 4 mm Gas Outlet – Bottom (Pack of 50)
    • RR91061: Nitrile O-Rings 3 mm Gas Outlet – Top (Pack of 50)
    • RR91062: Viton O-Rings 4 mm Gas Outlet – Bottom (Pack of 50)
    • RR91063: Viton O-Rings 3 mm Gas Outlet – Top (Pack of 50)