Receiver Adapter, Bent With Vacuum Connection, Socket To Cone

Quick Answer: A bent vacuum receiver adapter is a glass bend with a socket at the top for the condenser cone, a cone at the bottom for the receiving flask, and a side tube for vacuum tubing. It lets a distillation set be evacuated from the receiver end.

Where the Pump Connects

In vacuum distillation the pump is joined to the apparatus after the condenser, never at the boiling flask, so that vapour is condensed before it reaches the line. This adapter provides that point. Its side tube, usually finished as a hose olive, takes thick-walled vacuum tubing that runs to a cold trap and then to the pump or water aspirator. The socket-to-cone design lets it sit between a condenser outlet cone and a receiver with a ground neck, so the whole train can hold a vacuum.

The same side tube is useful at normal pressure. Left open, or fitted with a calcium chloride guard tube, it vents the apparatus; with tubing attached, it leads uncondensed vapour towards a fume cupboard; joined to a nitrogen line with a bubbler, it keeps air away from a distillate that oxidises or absorbs moisture.

The title gives no joint sizes. The socket must match the condenser outlet and the cone must match the receiver neck, and the side tube should suit the bore of the vacuum tubing you use.

Applications

• Reduced-pressure distillation of high-boiling or heat-sensitive liquids
• Removing solvent under reduced pressure when a rotary evaporator is not available
• Distilling under a nitrogen blanket through the side tube, with an oil bubbler as the outlet
• Venting an atmospheric distillation through a drying tube to keep moisture out of the receiver

Specifications

Care & Handling

• Evacuate round-bottomed receivers only; flat-bottomed and conical flasks can implode.
• Put a cold trap between the side tube and the pump so solvent vapour does not reach the pump oil or the drain.
• Grease every joint lightly and clip it; an ungreased joint leaks under vacuum and a loose one can pull apart when air is let back in.
• Let air back in slowly through the line after the flask has cooled, never by pulling a joint apart.

Why Choose LabEquip

Pharmacy colleges, postgraduate chemistry labs and process-development groups buy this adapter whenever they distil under reduced pressure. It fits the vacuum distillation assembly listed under LabEquip chemistry lab equipment, and joint sizes can be matched to your condenser through the contact page.

Frequently Asked Questions

Why is the vacuum connected at the receiver adapter and not at the flask?

Connecting after the condenser means vapour is condensed and collected before the gas stream reaches the pump. Pumping straight from the boiling flask would draw hot vapour and liquid into the line and cut the yield.

What tubing should be attached to the side tube?

Thick-walled rubber or other vacuum-rated tubing, which does not collapse when evacuated. Ordinary thin laboratory tubing flattens under vacuum and blocks the line.

Can the adapter be used at normal atmospheric pressure?

Yes. Leave the side tube open, or fit a guard tube if the distillate must be kept dry. The side tube then acts as the vent that stops pressure building up in the heated apparatus.

Which receiving flasks are safe under vacuum?

Round-bottomed flasks, including pear-shaped types, free of cracks and deep scratches. Flat-bottomed and conical flasks are not designed to withstand external pressure.

How do I change fractions with this adapter?

With a single receiver, remove the heat, let the flask cool a little, admit air slowly, swap the receiver and pump down again. To avoid breaking the vacuum, a multi-limb adapter that rotates between several flasks is used instead.

How should I clean the side tube?

Rinse it with a suitable solvent while the adapter is still assembled, then wash the whole piece in warm detergent solution. A narrow brush or pipe cleaner reaches into the olive, where residues from vacuum work collect.

Last Updated: September 2026