A pressure switch is a switch that turns off a machine or unit when the pressure inside the unit becomes too high or too low. The pressure switch works by making electrical contact when the machine or unit reaches a certain predetermined pressure reading. This is a safety additive that many pressure-building machines use to keep the machine from exploding or pressures from falling too low in applications where low pressure can cause problems.
Pressure switch manufacturers make two different forms of pressure switches for different applications. The two main kinds of pressure switches include the pneumatic switch and the hydraulic switch. Usually, pneumatic switches are used with pneumatic machines and hydraulic switches are used with hydraulic machines. The use of the switch will vary depending on the machine, but in general, both pneumatic and hydraulic switches are used for specific purposes, such as:
Pneumatic switches: A pneumatic switch can turn off an electric gas compressor when the pressure level inside the reservoir reaches a certain level. The switches and also control the cell-charge levels inside a battery. Sometimes these switches are used to turn off a compressor when the machine has no feed during the suction process. They are also used in airplanes to warn a pilot or passengers of cabin pressure changes.
Hydraulic switches: Hydraulic switches are usually used in vehicles to monitor pressure changes. A hydraulic switch may be used to turn on a warning light if the engine oil pressure falls to low, or to turn on brake lights when pressure is applied to the brakes. The switch can also help prevent transmission torque convertors from locking up during use. Hydraulic switches are also used to monitor the pressure changes in bag filtration systems and can trigger an alarm when air pressure gets too low.