Question - Why is the Orifice tab provided? 
          
        
        Answer - 
        
Following reasons justify for providing orifice tab:
- Indication of the orifice plate in a line
 - The orifice diameter is marked on it.
 - The material of the orifice plate.
 - The tag number of the orifice plate.
 - To mark the inlet of an orifice.