There are 4 different nozzle springs I use. Each work at a different opening/closing pressure, or check valve operating pressure. You don't want to operate your pump right at the open/closing pressure. You will understandable get erratic and poor mist productions. Make sure you a good 30-50 psi above it so the check valve stays completely open.
Above are two springs, a smaller or light gauge spring and a larger, or heavier gauge spring. The smaller opens/closes at around 30-40 psi with good spray/mist at around 60-80 psi. The larger opens around 250-300 psi with good spray/mist around 350-400 psi. There are two others in-between. One operates at around 150psi and the other at around 200psi.
The larger springs are used with smaller orifice nozzles. These are the 0.08mm, 0.10mm, and 0.15mm nozzles. They are used here because these nozzles work better at higher pressures between 400 and 1000 psi. They give off a good low micron mist plume. They will work OK at lower pressure, around 300 psi but the mist production is not a good. The 0.08mm barely puts out a mist at 300 psi and has a tendency to spit larger droplets of water. The 0.10mm is just about the same as the 0.08mm. The 0.15mm work fairly well at 300 psi but noticeably better at 500 psi
Larger orifice nozzles, 0.20mm and above, can use the smaller spring effectively, and are designed to work better at lower pressures. You can use a larger orifice at higher psi, 500-1000, however the mist is quite large and one could say, uncontrollable. However if this what you want, fine.
So, what it comes down to is that the smaller springs can be put into small orfices but the quality mist output get questionable. 0.10mm will work at 250-300 psi but lower than that the mist and plume quality tapers off.