3. Determining an attack system

3.1 Basic formula

The equivalent flow rate of a system is directly related to the metallostatic load H or H _eq under which it operates, i.e. the difference in level between the free surface in the pouring basin (or in a pouring funnel, to a permissible approximation) and the level where the alloy is at atmospheric pressure.

In a well-designed system, where there is no detachment of the alloy's fluid threads along the walls, this elevation coincides either with the outlet of the alloy jet in the case of drop casting (Figure