Hi,

1. What is the proper shot flow (kg/min or lbs/min) verification tolerance for shot peen/glass bead machines?
I can't find anything about this in AMS 2430.

2. What is the effect of to heigh/low shot flow? Does this affect the part in other ways than coverage?

Please advice.

I am not aware of any specified requirement for shot flow verification. Users specify both peening intensity and coverage. It is up to the shot peener to achieve both requirements. Coverage rates would obviously be affected by the shot flow rate. There is, however, an indirect effect of shot flow rate on peening intensity. High flow rates will generate lower peening intensities than low flow rates - other parameters being kept constant.

It is in the peener's best interests to ensure that flow regulation equipment e.g. Magnaflow, is properly maintained and calibrated.

Flow rate limits are listed in AMS2432, Shot Peening, Computer Monitored with ±10% Process Tolerances Shutdown Limits.
AMS2430 does not require computer monitoring and thus the limits are not included in that specification.
High or low media flow rates in air blast machines will affect the media velocity and hence the intensity of peening. Low media flow rates will have higher velocities than high media flow rates. Thus it is common to use a very lean (low) media flow rate to achieve a higher intensity (but at the penalty of longer time to achieve coverage).