code: def len_cdc_tube(FlowPlant, ConcDoseMax, ConcStock,
                   DiamTubeAvail, HeadlossCDC, LenCDCTubeMax, temp,
                   en_chem, KMinor):
     
     index = i_cdc(FlowPlant, ConcDoseMax, ConcStock,
                  DiamTubeAvail, HeadlossCDC, LenCDCTubeMax, temp,
                  en_chem, KMinor)
     len_cdc_tube = (_length_cdc_tube_array(FlowPlant, ConcDoseMax, ConcStock,
                                          DiamTubeAvail, HeadlossCDC, temp, en_chem,
                                          KMinor))[index].magnitude
  
     return len_cdc_tube
docs: The length of tubing may be longer than the max specified if the stock
     concentration is too high to give a viable solution with the specified
     length of tubing.