Calibrate Pressure Switch?

[Mark Sheridan]

Originally Posted by lonnie lascelle

Calibrating the pressure switch is possible. There is a setscrew on the side which is allen head, the manufacturer has originally set them and put silicone around the threads where the plastic meets metal base. That is what the set screw is for. Take a utility knife score the silicone and peal it out. Loosen setscrew pressurize system, adjust pressure switch by threading the top and bottom half in or out (A little adjustment goes a long way). Adjust to the proper cut in/out pressure, tighten setscrew, reverify pressures, re-silicone – done.

I do this too for the Nason SM model but apparently the SM model is not marketed as field adjustable. Only the CJ model is marketed as field adjustable.
http://www.nasonptc.com/pdfs/Switches_Catalog.pdf

I could not find a source indicating the SM model is ok for field adjustments. As far as I can tell, the manufacture never intended for the SM model to be adjusted by the user.

So would this be an illegal modification to a pneumatic component? Luckily I have a pair of factory set SM models as replacements.