Retsch GM 300 - Manual (Page 33)

Cleaning and service
33
Under certain conditions there may be corrosion on metallic parts. This is not a
quality defect and can occur despite best material quality.
Fig.19: Protective oxide layer
The resistance of “stainless” steel is attributable to an extremely thin invisible
protective oxide layer (S), the so-called passive layer.
Since the grinding tool surfaces are exposed to mechanical load, small areas of
corrosion (K) may appear after this protective oxide layer has been damaged.
• This corrosion can be prevented if you dry the grinding tools after rinsing.
In the case of the steel used by Retsch, the protective layer is automatically
continuously formed through a reaction with oxygen (O
2
).
• Should areas of rust develop despite this, they can be removed by vigorous
polishing.
Fig. 20: Ring seal
NOTE
• Check the state of the V-ring seal (V) regularly.
– The bottom edge of the lip seal (DL) must be clean and smooth.
• Replace the V-ring seal when the lip seal is brittle, cracked, frayed or
damaged in order to prevent rust and damage to the cutter bearing.
(V-ring seal part number: 05.111.0243)
V
DL