Where streaks come from
Sprays of adjacent nozzles must overlap on the strip; otherwise impact dips at the seams and leaves longitudinal streaks — the classic sign of incomplete descaling.
Rules of thumb are only a start
A 10–20% overlap of coverage width is a common starting point, but the real answer comes from measurement: map the impact distribution of the full row on a two-axis rig, then set spacing and angles.
The cost of over-overlap
More overlap means repeated impingement: more water, more strip cooling, possible edge over-cooling. Descaling saturates; extra overlap only adds cost.
General industry knowledge; confirm parameters against your process and measurements.