```pascal
FUNCTION "ValveFlow" : Real
{ S7_Optimized_Access := 'FALSE' }
AUTHOR : 'Author'
FAMILY : 'Function'
NAME : 'Name'
VERSION : 1.0
   VAR_INPUT 
      i_DeltaP : Real;
      i_ValveOp : Real;
      i_KFF : Real;
      i_Dens : Real;
   END_VAR


BEGIN
	    IF #i_KFF <> 0 AND #i_DeltaP >= 0 AND #i_Dens <> 0 THEN
	        #ValveFlow := #i_ValveOp * SQRT(#i_DeltaP / #i_Dens) / #i_KFF ;
	    ELSE
	        (* classic code: #ValveFlow := 0.0;*)
	        #ValveFlow := REAL#0.0;
	  END_IF;
	
	
END_FUNCTION


```