FRITSCH PULVERISETTE 5/4 classic line - Manual (Page 48)

7.2 Grinding in inert gas with gassing lid
NOTICE!
Observe imbalance offsetting! (See Ä Chapter 6.6 ‘Mass
balance’ on page 37).
We carry out a worker water bath test on all gassing lids.
The part to be tested is sealed, a pressure of 5.5 bar is
applied and it is immersed in a water bath. If there is a leak,
bubbles will develop. The air bubbles that develop within a
specific interval are evaluated by the worker/tester.
Only gassing lids with a leak rate of <10
‐4 [mbar l/s] are
approved.
When grinding in inert gas, the same conditions apply regarding
clamping and composition of grinding set and balls, as apply for standard
grinding.
Two valves are screwed onto the gassing lid through which you can feed
in inert gas (e.g. nitrogen) before switching on the mill. A Viton flat seal is
used instead of a Teflon one.
7.2.1 Preparation for gassing
a Gassing hose
b Hose clamp
c Coupling
d Valves
e Ventilation attachment
n Fill the grinding bowl with grinding balls and grinding stock. (See
Ä Chapter 6.3 ‘Filling the grinding bowl’ on page 33)
n Attach the Viton seal and lid.
n Insert the grinding bowl into the grinding bowl holder (8).
n Clamp the grinding bowl in the device (See Ä Chapter 6.5.1
‘Clamping with the "Safe‐Lock" (5) tensioning device’ on page 35)
Using the additional clamping system, the following steps can also be
completed in the glove box and subsequently clamped in the Planetary
Mill:
n Connect the gassing hose (a) to the inert gas supply using the pro-
vided hose clamp (b).
n Screw the ventilation attachment (e) onto one of the two valves (d).
n Place the coupling (c) of the gassing hose on the free valve. When
doing so, press the lever of the coupling and push the coupling along
the neck of the valve until it goes no further. Release the lever.
Accessories
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