code: def headloss_fric(FlowRate, Diam, Length, Nu, PipeRough):
      
      #Checking input validity - inputs not checked here are checked by
      #functions this function calls.
      ut.check_range([Length, ">0", "Length"])
      return (fric(FlowRate, Diam, Nu, PipeRough)
              * 8 / (gravity.magnitude * np.pi**2)
              * (Length * FlowRate**2) / Diam**5
              )
docs: Return the major head loss (due to wall shear) in a pipe.
  
      This equation applies to both laminar and turbulent flows.