def hydraulic_losses_suct_feed(dzeta_enter_feed, dzeta_turn90_feed, n_turn90_feed, dzeta_ventil_feed, n_ventil_feed, g, w_liq_real_enter_feed):
    """
    Calculates the hydraulic losses of suction line.
    Parameters
    ----------
    dzeta_enter_feed : float
        The local resistance of tube enter, [m]
    dzeta_turn90_feed : float
        The local resistance of turn to 90 degrees, [m]
    n_turn90_feed : float
        The quantity of turn to 90 degrees, [dismensionless]
    dzeta_ventil_feed : float
        The local resistance of ventil on sunction line, [m]
    n_ventil_feed : float
        The quantity of ventil on suction line, [dismensionless]
    speed_suction : float
        The speed of suction line , [m/s] 
    Returns
    -------
    hydraulic_losses_suct_feed : float
        The hydraulic losses of suction line, [m]
    References
    ----------
    &&&&
    """         
    return ((dzeta_enter_feed + dzeta_turn90_feed + dzeta_ventil_feed) * w_liq_real_enter_feed/(2 * g))