Mechanical expansion joints in a piping system outside of a cargo tank:
    
    
        
        (a) 
         May be installed only if offsets, loops or bends cannot be installed due to limited space or piping arrangement;
     
    
        
        (b) 
         Must be a bellows type; and
     
    
        
        (c) 
         Must not have insulation or a cover unless necessary to prevent damage.