considerations:
Pump Switches have wide differentials compared to 'regular' pressure switches, but the differential range generally maxes out at 30 psi.
These pump control switches are all diaphragm activated switches. The specs for Grainger's 60-80 psi pump switch are posted below. Note the max pressure at 100 psi. Although it is burst pressure rated to 300 psi, the switch's repeatability, life and reliability is exceeded at pressures above the rated pressure.
Statement from Square D's specs (who makes similar, if not identical style switches):
During the normal operating cycle, system pressure should never exceed the upper limit of the range when using a diaphragm actuated switch. This will greatly reduce the life of the diaphragm. (pg 6)
con't:
Maximum allowable pressure is the pressure to which a switch can be subjected without causing a change in operating characteristics, shift in settings, or damage to the device.
Pressure surges may occur in a system during the start up of a machine or from valve operation. Surges are not normally detrimental to the life of a switch if the surge is
within the maximum allowable pressure rating of the switch. Diaphragm actuated switches should not be subjected to more than 10 surges per day. More frequent surges will greatly reduce the life of the diaphragm.
Square D's FSG/FYG/FTG max out at rated pressure below 100psi
Square D's FRG/FHG & 9013G Series max out at rated pressure above 100psi
The FSG is the shrink wrapped product one finds in hardware, home improvement, and farm supply stores in USA rural areas for properties with residential wells with holding tanks.
Switches with higher pressure ratings are more likely to be available from specialty distributors, not the hardware store.
Square D's FRG also offers these features:
Pump shut down application:
The 9013FRG reverse action pressure switches
can be wired in series with the FSG standard
action normally closed (N.C.) pressure switches
to automatically shut off pumps in case of
emergency such as power loss or when a
pipe bursts.
Low level alarm application:
The 9013FRG reverse action pressure switch
can be set to trigger an alarm based on the
low pressure conditions.
Manual on/off switch:
The 9013 series offers an optional on/off lever
for the pressure switch. This allows you to
manually turn on and off your pump system for
extended periods of time such as when you are
going to be away or have remote locations not
regularly in use.
Automatic low pressure/water cut-off
If system pressure is lost for any reason, a low
water condition for example, the automatic
low pressure/water cut-off feature will open
the contacts, turning off the pump. The low
water cut off functions normally and cycles the
pump per your typical demands, however, if
the system pressure is lost for any reason, the
switch contacts open, turning off the pump.
(from a data sheet, pg 4, at