The 578-24 MagnaValve can be calibrated in metric to 0-10 Kg/minute. It will work with cut wire abrasive but only if it is pre-conditioned to become round (spherical).
You would normally use chart #1 for peening applications. Chart #2 is provided for reference only. It shows the maximum amount that can be delivered but this is wasteful and actually reduces the peening intensity.