NCF fan
EN
6.1 Visual inspections of blades and casing
• Periodical visual checks must be made for wear on impeller blades, given that deterioration of these parts can
create a condition of extreme risk, due to the ejection of the blade or the failure of structural components,
with consequences that may even be fatal.
• To monitor phenomena of abrasion on impeller blades and the casing, use a portable lamp to visually inspect
components, slowly rotating the impeller to allow all blades to be seen. Blades must be totally free from dam-
age and must show no signs or abrasion or missing sections.
With regard to the phenomenon of corrosion on impeller blades and the casing, corrosive and acidic environ-
ments can reduce the thickness of NCF fan safety components. This phenomenon must not be underestimated,
also because it does not depend solely on the concentration of aggressive agents. Condensation may form dur-
ing pauses in NCF fan operation, and this may accelerate the phenomenon of chemical corrosion, which in turn
may alter the thickness of components, affecting their integrity.
Components to check
Type of check/instru-
ment
Criteria for acceptabil-
ity
Result
Impeller: blade thickness
Dimension/Caliper
Reduction of thickness
no greater than 10% in
an area without wear or
with paint undamaged
Impeller: thickness of im-
peller disk
Dimension/Caliper
Reduction of thickness
no greater than 10% in
an area without wear or
with paint undamaged
Casing: thickness of
sides and sheeting
Dimension/Caliper or
equivalent
Reduction of thickness
no greater than 10% in
an area without wear
Intake: thickness
Dimension/Caliper
Reduction of thickness
no greater than 20% in
an area without wear or
with paint undamaged
Anti-vibration joints:
thickness of anti-wear
sheeting (if present)
Dimension/Caliper
Reduction of thickness
no greater than 20% in
an area without wear or
with paint undamaged
Welding (entire struc-
ture)
Visual
Absence of damage and
cracks
Date:
Signature:
6.2 Checking and cleaning parts in contact with the fluid
• The fan impeller should be cleaned regularly to prevent vibration caused by dust accumulating on the blades
during operation.
• If the NCF fan is used to pump even slightly dusty air, air containing abrasive powders or for the pneumatic
transport material, the cleanliness and wear of the impeller must be checked regularly. Dirt deposits on the
impeller or wear of parts of the impeller can cause undesirable vibrations during fan operation.
• If any part of the impeller is excessively worn, it is imperative that the impeller be replaced. For this and before
carrying out any modification to one of our fans, please contact Nedermanl and quote the part number found
on the fan identification plate.
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