code: def _Backward2_T_Ph(P, h):
      
      if P <= 4:
          T = _Backward2a_T_Ph(P, h)
      elif 4 < P <= 6.546699678:
          T = _Backward2b_T_Ph(P, h)
      else:
          hf = _hbc_P(P)
          if h >= hf:
              T = _Backward2b_T_Ph(P, h)
          else:
              T = _Backward2c_T_Ph(P, h)
  
      if P <= 22.064:
          Tsat = _TSat_P(P)
          T = max(Tsat, T)
      return T
docs: Backward equation for region 2, T=f(P,h)
  
      Parameters
      ----------
      P : float
          Pressure, [MPa]
      h : float
          Specific enthalpy, [kJ/kg]
  
      Returns
      -------
      T : float
          Temperature, [K]