Radleys GreenHouse, Instructions Manual, Page: 15 / 16

The GreenHouse Blowdown Evaporator are supplied as standard with Silicone
Rubber Gaskets (RR99606) in the Base Unit and the Reflux and Additions Heads
(if supplied). These gaskets are suitable for the majority of applications but in
some cases the optional Viton Rubber Gaskets (RR99605) will be more suitable.
When to use the Silicone Rubber Gaskets
The Silicone Rubber Gaskets will be suitable for most applications and show
good resistance to most common organic solvents and reagents including
acetone, acetonitrile, alcohols, acetic acid, esters, DMF, DMSO and mineral
acids and bases etc. It should be borne in mind that resistance testing is
normally done with the material totally immersed in the solvent, whereas with
the GreenHouse Blowdown Evaporator in normal operation the gaskets should
only be exposed to low concentrations of vapours from solvents and reagents.
Silicone Rubber shows poor resistance to trifluoroacetic acid (TFA) and therefore
Viton may be preferred for applications involving this solvent.
When to use the Viton Rubber Gaskets
Viton shows superior resistance to chlorinated hydrocarbons such as
dichloromethane and chlorobenzene compared with Silicone Rubber. It is also
more resistant to aromatic hydrocarbons. Viton exhibits relatively good resistance
to trifluoroacetic acid (TFA) and is the preferred gasket in this case.
Thermal Resistance of Gaskets
Both the Silicone Rubber and Viton Gaskets have service temperatures well
in excess of the normal maximum recommended operating temperature of the
GreenHouse (ca 150˚C).
In normal use the GreenHouse Blowdown Evaporator will not be used at
temperatures much above 40˚C.
GreenHouse Blowdown Parallel Evaporation System
Choosing the Correct Gasket
Replacing the Gasket
How long should the gasket last ?
The gaskets are a consumable item and they will need replacing. How long
they last depends very much on what you expose them to. Repeatedly splashing
solvents and reagents directly on to the gaskets will greatly reduce their life.
RR99605 - Viton Rubber Gaskets, pack of 2
RR99606 - Silicone Rubber Gaskets, pack of 2
Changing the Gaskets
The Gaskets should be inspected regularly and replaced when they show signs of
deterioration or embrittlement. They can easily be removed with a pin or
something similar, taking care not to damage the groove in which they seat. The
new gaskets are then simply pushed into place ensuring that they are properly
located in the machined grooves. You will not require glue or sealant to hold the
gaskets in place.
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