Gilson 402 - Manual (Page 86)

6-2
Maintenance
6
Cleaning
Cleaning
Cleaning the Exterior
The instrument cover and front panel may be cleaned.
Ensure that the instrument is switched OFF and the
power cord is removed when you clean the instrument.
When you need to clean the instrument, use one of
the three following methods:
1) A clean dry cloth.
2) A cloth dampened with water.
3) A cloth dampened with soapy water.
If a cloth dampened with soapy water is used to
clean the instrument, only domestic soap may be
used. No other form of detergent or chemical may
be used.
Parts in the liquid flow path may be cleaned with
ethanol or bleach (10 % Sodium Hypochlorite).
Cleaning the Valve
The valve must be cleaned after using the 402 with
corrosive or hazardous liquids, if leakage has
occurred, or if liquid flows back into the waste
tubing, or if the dilutor has been left unused for a
while after pumping alcohol based liquids. The
valve must be dis-mounted from the 402 and
separated from the syringe, then disassembled. The
valve can then be cleaned or autoclaved. It is not
necessary to autoclave the valve axle or the spring.
The surfaces of the ceramic
stator and rotor inside 402’s
valve are treated to give
optimum airtight operation. If
the valve has been used with
alcohol based liquids, and then
left unused for a while, a
grinding noise may be heard
during valve switching the
next time the pump is used.
This is because of friction
between the ceramic surfaces.
To correct this problem, you
should disassemble the valve
and clean the ceramic surfaces
with a damp cloth.
Dismounting the Valve
1) Disconnect all tubings from the valve.
2) Separate the syringe from the valve.
3) Undo the two screws securing the valve to the
402 front plate and remove the valve.
Disassembling the Valve
Hold the valve body firmly in one hand, undo the
valve axle guide, using a 17 mm open ended spanner.
Separate the axle guide from the body of the valve.