Figure 3-3. Piston Pressure Switch.
Diaphragm Pressure Switch. The diaphragm pressure switch consists of a housing, a diaphragm, an
adjustable spring to load the diaphragm, a microswitch, and linkage for transmitting movements of the
diaphragm to the microswitch. The housing has ports for the same functions as those in the piston
Pressure Switch Operation. The two types of pressure switches have the same operating principles;
only the piston one is covered here. Fluid pressure enters the pressure port and moves the face of the
piston against the adjustment spring.