43
Slide valve mechanisms can get “gummed up” due to reaction product leakage, reagent spillage, improper cleaning, etc.
The SiliCycle MiniBlock can be dismantled (Figure 45) to facilitate manual cleaning. Replace all Compressor Cords at this time.
A rigorous cleaning using an ultrasonic bath may help in disengaging the slide valve (see section 6.1.2 SiliCycle MiniBlock Cleaning).
There are five (5) basic places where solution leakage or solvent loss can occur. These points are depicted in Figure 44 and explained below:
Reaction Tube
Frit
Pinch Tube
Female Luer Fitting
Male Luer Fitting
Figure 44: Leakage Points
Excessive evaporation can be caused by tube height unevenness. Worn Pinch-Tube Inserts (female luers) can cause this, as the Reaction Tubes sink
too far down into the luer fitting. Leaving SiliCycle MiniBlocks clamped for extended periods can also cause Reaction Tubes to sink too far into
the luer fittings.
Worn Valve Inserts should be replaced. Solvent loss at the top of the Reaction Tubes can also be lessened through use of a better
septum. Septum materials and functions are described in Section 2.3 SiliCycle MiniBlock System Materials.
Match septum to your application. The new Multi-Layer Septa are designed to reduce solvent loss. Excess solvent loss over time
can result from venting SiliCycle MiniBlock reactions through an Inert Atmosphere Manifold and bubbler apparatus.
Where possible, minimize evaporative loss, through selection of a solvent with a low vapor pressure
at the reaction temperatures.