BRAND Dispensette S Instrucciones De Manejo página 68

9 Cleaning
a.
9.3.2.2 Replacing the filling valve
b.
9.3.2.3 Dislodging a stick valve ball
9.4 Replacing the dispensing cartridge
The dispensing unit is a wear part and must be replaced according to the specific conditions of use.
The replacement interval depends on the medium used and number of dispensing cycles, whereby re-
placement is to be expected at the latest after 10,000 full strokes (medium: distilled water). Please
note that media residues can accumulate inside the dispensing unit; these can be released by tilting
the instruments or dispensing unit. If drops of media are observed on the outside of the dispensing
cylinder or in the retaining ring, immediately check the instrument and replace the dispensing unit. If
hazardous media (e.g., hydrofluoric acid or bromine) are dispensed, replace the dispensing unit after
approx. 3000 complete strokes. Replacement may also be necessary earlier depending on the medium
dispensed and the frequency of use.
68
Operating manual
a.
After disassembling the discharge tube (see Replacing
discharge tube, p. 67), use the assembly tool to unscrew
the discharge valve.
b.
Firmly screw in the new discharge valve first by hand
and then tighten it with the assembly tool. The thread
should not be visible.
a.
Pull out the recirculation tube and the telescopic filling
tube.
b.
Use the assembly tool to unscrew the filling valve.
c.
Screw in the new filling valve first by hand and then
tighten it with the assembly tool.
If the instrument does not fill up, and if some elastic resis-
tance is evident when the piston is pulled upward, then it is
possible that the valve ball is stuck.
In this case, dislodge the valve ball using light pressure; for
example, with a 200 µl plastic pipette tip (see the figure at
the side).
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