ASSEMBLING APPARATUS

Chemical glassware are connected together using quick fit or conned socket joints.                                      
These come in various sizes named B14, B19, B24 and so on.                
But all of them have the same tapper so that cones and sockets of the same number fit together exactly.
In cases where it is necessary to join cones and sockets of different sizes, adapters are available.
Joints may be secured using plastic clips but this should not be relied upon to support the apparatus.

The clips are color coded according to the size of the joint they are designed to secure. It’s not often necessary to grease joints provided the glassware is going to be dismantled immediately after use.
A greasing is advisable for distillation under reduced pressure, for reaction under strictly anhydrous conditions and if a steam is used for heating. A light smear of grease should be applied on to the curve of the cone.

Never apply grease to the socket as it may be forced inside the apparatus contaminating the contents.
An alternative to greasing is the use of PTFE sleeves.
Tubing should never be forced over the glass side arm of the condenser. Side arms are easily broken and may cause injury.
The rubber tubing under glass should be wetted. Then the tubing will slide on easily.

Tubing should always pass well beyond the widest part of the side arm.
Soften plastic tubing by immersing it in hot water.
It will then slip easily unto the side arm.
Some condensers have detachable side arms which are attached to the condenser with the screw cap.
With this design, first put the tubing on the side arm, and then attach the side arm to the condenser.

Glass apparatus is support by metal clamps fixed to stand by bosses.
A boss is always attached to a stand so that the channel holding the stem of the tap faces upward providing freedom when the position of the stem is adjusted.

If the channel points downwards, the clamp can easily fall out of the boss during adjustment.
A clamp have fixed and adjustable jaws. It’s best to have the adjustable jaw on the stand side of the boss.
This way, the apparatus is supported centrally over the base of the stand and there is no danger of the stand toppling over.
When supporting a horizontal piece of glassware like a condenser, the opening jaw must be uppermost.
In this position, the apparatus is supported on the fixed jaw during adjustments.

If the moveable jaw is underneath, the whole apparatus will sink during adjustment and there is a danger it will fall out.
When setting up apparatus for distillation, always start by clamping the flask firmly but not too tightly.
Its position is adjusted using the boss screws one at a time.
Clamp screw for back and forth and to ensure the flask is vertical.
Stand screw from side to side or up and down.
Never support apparatus by clamping an adapter.
For distillation, the flask is connected to the condenser with the distillation head.

For simple distillation, joints are not greased.
Check that the condenser fits snugly unto the distillation head and secure the joint with the clip.
Connect a receiver adapter or takeoff band to the outflow of the condenser. Again, secure the joint with the glassware clip.
Support the receiving flask using a cork ring or lab jack.
When a steam bath is used as the heating source, condensate will collect on joints. And to prevent water sipping inside the apparatus, the joints must be greased.

A reflux condenser should always be supported using a second clamp and boss on the same stand.
Adjust the position of the clamp and rotate it on the stand until the condenser rest against the fix jaw of the clamp.
The clamp should not hold the condenser tightly. Its purpose is to prevent the condenser toppling sideways.
Add a drying tube with a lightly greased joint if the reflux is to be performed under anhydrous conditions.
In the reflux apparatus, all components are held together by gravity. So glassware clips are not needed.
It is essential to secure tubing if the experiment is to be left unattended over lunch or overnight.

Both rubber and plastic tubing should be secured with wire.
Alternatively, plastic ties can be used in place of wire.
Even when tubing has been secured, if the apparatus is to be left unattended, it must always have a safety card leaving necessary information for an emergency shutdown.