def _Backward2_T_Ph(P, h):
    """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]
    """
    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