code: def _k_value_square_reduction(ent_pipe_id, exit_pipe_id, re, f):
      
  
      if re < 2500:
          return (1.2 + (160 / re)) * ((ent_pipe_id / exit_pipe_id) ** 4)
      else:
          return (0.6 + 0.48 * f) * (ent_pipe_id / exit_pipe_id) ** 2\
              * ((ent_pipe_id / exit_pipe_id) ** 2 - 1)
docs: Returns the minor loss coefficient for a square reducer.
  
      Parameters:
          ent_pipe_id: Entrance pipe's inner diameter.
          exit_pipe_id: Exit pipe's inner diameter.
          re: Reynold's number.
          f: Darcy friction factor.