If the pressure switches are the same, you can exchange the contact blocks from one to another or also exchange the springs. Before unscrewing to change the springs, count the turns you have to return them to the same on the other pressure switch and look at the clock after changing springs that the pressure is between 40 pounds high which is when you turn off and 20 pounds low It is when you turn on to return to 40 pounds. It may also be that the pressure switch works between 25 max and 15 min or also in atmospheres between 1.8 max and 1.1 min I hope I have helped my friend Jose ', I don't know if you have already solved, I have not been in the forum for personal problems, so what I can say is that you upload photos of the new pressure switch to see how it is. In any case, if it has 1 large central spring and a small lateral spring, the center one controls the on and off pressure; the small side controls the differential. It means that only when moving the large pipeline that the required pressure can be achieved. the minimum also goes down and had to turn on when going down to 10 or 15 pounds. If it doesn't turn on, then unscrew the smaller screw to remove differential pressure and make it turn on. It is a test game until you can adjust the pressures to turn on and off wherever we want. Note that the differential screw is only the one that regulates the distance between start and stop but the large spring is the one that regulates the minimum and maximum pressures. I hope I have been clear now