Heidolph Heat-On - Manual (Page 4)

Page 3
Safety Information
The following symbols are intended to assist the
user in the safe and efficient operation of Heat-On.
Important WARNINGS
1. Please read these instructions completely before using your Heat-On Block.
2. Operate only in a fume cupboard with protective safety sash.
3. During and after heating take care not to touch the Heat-On block.
4. Risk of burns from hot blocks
Like oil baths, Heat-On blocks remain hot for some considerable time after the heating source has been switched off. A temperature
probe or temperature sensitive label can be used to indicate when blocks are too hot to touch.
5. Flask selection process
Heat-On is designed so that over sized flasks cannot fit through the slightly narrower opening at the top of the block well. This means
that all suitable flasks should sit at the bottom of the block well, be a loose fit and as such spin freely in the Heat-On well.
When a flask is inserted into the well it is important to ensure that the flask touches the bottom of the well and does not ‘catch or stick’
on the sides of the block well. If the flask is ‘catching or sticking’ it may be deformed and may result in jamming and even cracking of
the flask when the Heat-On block is cooling.
There is a simple rule when using glassware with the Heat-on: “If it does not spin, then throw it in the bin”. If the flask does not
spin freely then it is unsuitable for use in the Heat-On and an alternative flask should be used.
6. Starting and stopping your reaction
In an ideal situation you should load your glassware into the block when the block is at ambient (room temperature).
However in certain situations this may not be practical. In such circumstances you should note:-
a. You can use cold water to cool the block down rapidly, but take care with blocks above 100˚C as steam is a potential hazard.
b. It is generally safe to insert flasks into blocks that are below 50˚C, but the flask should be removed before the block temperature
drops below the start temperature as there is a small risk that the contraction of the block could crush the glass flask.
c. In all eventualities flasks should be removed at or above the temperature they were originally inserted; i.e. in the case of a flask
that is inserted at 80˚C, it should be removed when or before the block cools to 80˚C.
7. Chemical resistance
Anodised Heat-On blocks are resistant to the majority of solvents and splash resistant to dilute acids and alkalis at room temperature.
The fluoropolymer coated Heat-On blocks offer superior resistant to the majority of solvents, acids and alkalis.
Extended exposure to acids or alkalis will attack the surface of the Heat-On blocks. The stronger the concentration and the longer the
exposure time the more chance and intensity of any attack. Heat will also speed up and intensify any attack. e.g. hot concentrated
sulphuric acid will damage the fluoropolymer coated Heat-On blocks over a period of time. It is important to clean off any residual
chemical spills immediately after they occur.
8. Temperature range
Heat-On blocks can be used up to 200˚C without damage to the block. Temperatures up to 260˚C can be achieved but some minor
surface degradation may occur.
Warning
Applies when there is a possibility
of personal injury.
Important Note
Alerts the user to important facts.
Heat-On Instructions
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Important, Important,
Important, Important,
Important, Important,
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Important, Important,
Heidolph-Heat-On Instructions 23-03-09:2nd draft amends 16-03-09 23/3/09 15:37 Page 4