9.3.1 To a limited degree, internal visual inspection
                           will reveal damage at an early stage. Diagnostic monitoring systems
                           should be used as they greatly assist in maintaining the effectiveness
                           of the equipment. By fitting two equal-sized blowers or, alternatively,
                           supplying and retaining on board a spare impeller with a shaft for
                           each blower, an acceptable level of availability is ensured. Visual
                           inspection through the available openings in the blower casing is
                           adequate for this purpose.
                        
                        
                        
                      
                     
                     
                     
                        
                        
                         
                           9.3.2 An inspection of inert gas blowers should
                           include:
                        
                        
                        
                        
                           - 
                              
                              
                              
                                 .1 internal inspection of the blower casing for
                                 soot deposits or signs of corrosive attack;
                               
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                                 .2 examination of fixed or portable washing system;
                               
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                                 .3 inspection of the functioning of the fresh
                                 water flushing arrangements, where fitted;
                               
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                                 .4 inspection of the drain lines from the blower
                                 casing to ensure that they are clear and operative;
                               
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                                 .5 observation of the blower under running conditions
                                 for signs of excessive vibration, indicating too large an imbalance.