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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def API520_A_steam(m, T, P1, Kd=0.975, Kb=1, Kc=1):
    r'''Calculates required relief valve area for an API 520 valve passing
    a steam, at either saturation or superheat but not partially condensed.

    .. math::
        A = \frac{190.5m}{P_1 K_d K_b K_c K_N K_{SH}}

    Parameters
    ----------
    m : float
        Mass flow rate of steam through the valve, [kg/s]
    T : float
        Temperature of steam entering the valve, [K]
    P1 : float
        Upstream relieving pressure; the set pressure plus the allowable
        overpressure, plus atmospheric pressure, [Pa]
    Kd : float, optional
        The effective coefficient of discharge, from the manufacturer or for
        preliminary sizing, using 0.975 normally or 0.62 when used with a
        rupture disc as described in [1]_, []
    Kb : float, optional
        Correction due to vapor backpressure [-]
    Kc : float, optional
        Combination correction factor for installation with a rupture disk
        upstream of the PRV, []

    Returns
    -------
    A : float
        Minimum area for relief valve according to [1]_, [m^2]

    Notes
    -----
    Units are interlally kg/hr, kPa, and mm^2 to match [1]_.
    With the provided temperature and pressure, the KN coefficient is
    calculated with the function API520_N; as is the superheat correction KSH,
    with the function API520_SH.

    Examples
    --------
    Example 4 from [1]_, matches:

    >>> API520_A_steam(m=69615/3600., T=592.5, P1=12236E3, Kd=0.975, Kb=1, Kc=1)
    0.0011034712423692733

    References
    ----------
    .. [1] API Standard 520, Part 1 - Sizing and Selection.
    '''
    KN = API520_N(P1)
    KSH = API520_SH(T, P1)
    P1 = P1/1000. # Pa to kPa
    m = m*3600. # kg/s to kg/hr
    A = 190.5*m/(P1*Kd*Kb*Kc*KN*KSH)
    return A*0.001**2