Cleaning/Replacing Valves - BRAND Dispensette TA Operating Manual

Cleaning
Cleaning/replacing the valves
Warning! The cylinder, valve, telescoping filling tube and dispensing tube are full of reagent! For this
reason, always perform a standard cleaning before dismantling the instrument. The dispen-
sing unit must not be disassembled! Follow the safety instructions (see page 26)!
1.
Filling valve
a) Pull out the recirculation tube and the telescoping filling tube
(Fig. 1).
b) Use the mounting tool to unscrew the filling valve
(Fig. 2).
c) If the sealing ring is contaminated or damaged, carefully
remove it with a pair of curved forceps (Fig. 3).
d) Insert cleaned or new sealing ring.
e) Screw in the cleaned (e.g., in an ultrasonic bath) or new
filling valve first by hand and then tighten it with the
mounting tool.
2.
Discharge valve
The discharge valve is incorporated in the discharge tube. For
celaning see page 39. If necessary dismantle discharge tube and
clean it e.g. in an ultrasonic bath. Mount cleaned or new dischar-
ge tube (see page 30).
3.
SafetyPrime
For celaning see page 39. If necessary dismantle recirculation
volve and clean it e.g. in an ultrasonic bath. Mount cleaned or
new recirculation valve (see page 30).
Note:
If the instrument does not fill up, and if some elastic resistance is
evident when the piston is pulled upward, then it is possible that the
ball valve is merely stuck.
In this case, loosen the ball valve using light pressure, for example,
with a 200 µl plastic pipette tip (Fig. 4).
40
™ recirculation valve
1
2
3
4