Metrohm 807 Dosing Unit - Manual (Page 31)

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3 Installation
807 Dosing Unit
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Figure 16 Cylinder unit on the distributor
Removing the centering tube
Remove the centering tube as follows:
1 Remove the cylinder unit, comprised of centering tube, black cylinder
base, valve disc, dosing cylinder and dosing piston, from the distribu-
tor.
2 Carefully pull out the centering tube on the black cylinder base in an
upward direction.
You will now see the dosing cylinder on the black cylinder base with
the integrated valve disk.
You can now inspect the condition of the cylinder and the piston.
The glass cylinder should not exhibit any signs of corrosion. The plas-
tic coating PTFE of the piston should not be damaged in any way.
Figure 17 Dosing cylinder damaged