The picture on the left shows the basic reflux setup consisting of are heating mantle, a round bottom flask, a Liebig condenser used in reflux mode and a gas adapter on top. The picture on the right side shows the flask with a matching heating mantle and a stirring bar.

When you choose the size of your setup, keep the following things in mind:

1. Make sure that the flask is not more than half filled to allow enough room for expansion and boiling.

2. The entire setup is clamped at the neck of the flask (using a proper sized clamp). It holds the weight of the entire setup.

3. The inlet of the water is on the lower end of the condenser, the outlet at the upper end independent if the condenser is used for reflux or distillation. This way you will get away with a lower water flow for cooling, because the outer jacket of the condenser will fill up with water first before it reaches the outlet.

4. The heating mantle should fit the flask size. A heating mantle that is either too small or too big, has a poor contact with the flask, which damages the heating mantle. The lack of contact causes the heating mantle to overheat and burn out. A heating mantle that is slightly to big can be filled with sand to achieve a better heat transfer.

5. Most heating mantles have no temperature/power control. An external device has to be attached to control the power input. Never plug the heating mantle directly into a wall plug!!

6. If you heat a system, you need to have an 'overpressure valve' somewhere in your setup. It doesn't matter what you heat, the media always will expand (more or less) and will ultimatively build up a significant pressure, which can cause heavy explosions, followed by a fire if you heat flammable or pyrophoric materials. In many cases, you will connect it to the inert gas part of your Schlenk line. Make sure that you open it before you start heating.

7. Lubricate the joints lightly.

8. Lastly, don't forget to add a spin bar into your flask to mix the solution during the reaction/reflux.