Dishwashers use pressure switches that are similar to those used in washing machines. However, instead of having one switching point, they have multiple levels. For example, a two-position switch may switch at 10cm and 15cm of water, while a three-position switch may trip at 15cm, 25cm and 35cm of water.
Because they're not externally adjustable, they don't need to be located close to the control panel. Depending on your application, you might want your salvaged pressure switch to operate at pressures that are different to its standard range. That's not hard to do if you have a washing machine pressure switch, as they are quite easy to modify.In standard form, turning the adjustment control typically allows the trip pressure to be set to detect water depths anywhere from 9cm to 20cm. But if you remove the adjustment.