From Sciencemadness Wiki
Jump to: navigation, search

An adapter or connector is a type of laboratory item with ground glass joint, used to connect various glassware items, usually when making various setups, like distillation, refluxing, sublimation, inert gas environment, vacuum, etc.

Basic adapters

Bent adapter

A glass tube with male ground glass joints at both ends, used in distillations. There are two types: one bent at 75°, which is used to connect the distillation flask to the condenser and one bent at 105°, which is used to connect the condenser to the receiving flask. Some have a vacuum hose adapter.

Claisen adapter

Consists of a short straight glass tube with a curved lateral tube connected to the middle. It has two female ground glass joints and one male. This is the classical version, also called 3-way Claisen adapter. Some versions have two lateral curved tubes, giving it the appearance of a trident. This version is called 4-way Claisen adapter. One type of Claisen adapter had a bushing adapter in place of the straight tube joint.

Some Claisen adapters have a side stopcock on the curvature. These types are used when distilling solvents under inert conditions.

Connecting adapter

A three-way glass adapter, it had two male joints, one lateral and one in the lower side, and one female joint, in the upper side. The female joint is designed to hold a thermometer. Some models have different joint sizes for the female one, while others simply have a bushing adapter instead of the female adapter. Can have short or long arm, or multi-way.

Delivery adapter

Consist of an L-bent tube, with a female ground glass joint, they are commonly used in simple distillations.

Expansion socket adapter

Also called expansion adapter, they consist of a male and female socket which are connected. They are commonly used when connecting glassware with ground glass joints of different sizes. Bent adapters, often used in distillation, also exist. It's advised to not use more than one expansion adapter between two pieces of glassware, as the setup will become unstable or the joints may break from the weight distribution. Off-center models are also available.

Offset adapter

Consists of a warped glass tube connecting two ground glass joints, one male and one female.

Same socket adapter

Adapters with female to female or male to male ground glass joints, usually both the same size.

Straight connecting adapter

A straight glass tube with ground glass joints at both ends, either male/female, male/male or female/female.

Thermometer adapter

Also called thermometer well, it is a simple glass tube with a male ground glass joint in the superior part, used for holding a thermometer or thermocouple.

Vertical recovery still head

Used in distillation assemblies in which the condenser is assembled in the vertical mode. Some models have a splash head.

Y-shaped adapter

Consists of a Y-shaped glass tube with two female ground glass joints and a male ground glass joint. Commonly used in distillations, either as a replacement for the Claisen adapter or for attaching two condensers.

Advanced adapters

Bushing adapter with screw cap

Also called thermometer adapter, it has a glass body with a male ground glass and a glass screw. A plastic cap with a holed silicone rubber ring is used to tighten the item inserted in the hole, offering a good seal, though it does not hold on vacuum.

Cow adapter

A piece of lab glassware similar in appearance to a cow udder (hence its name), it is used together with a short-path distillation apparatus in vacuum distillation. The cow adapter consists of a round glass bulb (though some models lack the bulb), with a female ground glass joint, three male ground glass joints 45° apart and a hose adapter. A four-way adapter exists, though the main body has the shape of a square pyramid.

Kjeldahl delivery tube

Used in combination with a Kjeldahl flask during the Kjeldahl test.

Splash head

Found mainly in rotary evaporators, to prevent the boiling solvent bumping from reaching the cooling and the receiving flask. Other splash heads have a bent adapter and are used for steam distillation.

Stopcock adapter with socket

Glass adapter with female ground glass joint and Rotaflo® PTFE stopcock. Some models have plastic screwthread connector to allow rubber hoses.

Vacuum adapter

Contains a hose adapter with a male (most often) or female adapter (less common). It comes in various types, like straight or bent. More sophisticated models have a stopcock, to regulate the gas flow, while some can have two or three hose adapters, sometimes with their own stopcock. Other complex versions consist of a glass bushing adapter with a plastic hose adapter, which can be screwed in place.

Other adapters

Pouring adapter

A small beaker with a male ground glass joint in place of the bottom. Used to pour contents from a flask with ground glass adapter.


Ground glass adapters can be purchased from lab suppliers or online.

See also


Relevant Sciencemadness threads