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| REPAIRS ZONES OF PROPELLERS | |
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During operation, propellers are exposed to damages, wich must be it is recomendable to carry out the repairing or not. In order to do this, we need to divide the blade in three zones described as follows: |
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Zone “A”:
This zone is called the “Critical Area”, it is found between the hub and the 0.40R (see figure). In this zone, the repair by welding is not allowed, unless it has a special approval from classification society such as ABS, DNV, Lloyd Register, Bureau Veritas, etc.
Zone “B”:
In this area, very high operation stress can be developed, therefore, repairs by welding must be avoided as possible. Defects with depths smaller than 2 ml. can be grinded out.
Zone “C”:
In this area, repairs by welding are normally allowed. Operation stress are low. It is generally the thinnest section of the blade, in wich case the repair by welding is relatively safe. A repair method previously approved is required.
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