Pressure Switches are Everywhere!

June 20, 2013

You may not realize it, but pressure switches are all around us. In your home, vehicle, at work and the places you go around your community, pressure switches can be found operating in all sorts of devices. We have come to rely upon pressure switches to warn us of impending trouble with our vehicle’s oil or brake system, in airplanes to indicate a drop in cabin pressure, and many other instances where temperature, water and air pressure must be monitored to correctly operate machinery. What is a pressure switch? Essentially, a pressure switch is a type of switch that initiates electrical contact when the pressure level has reached a predetermined point. When this point is reached, electrical contact is made which normally turns on a warning light or warning sound. A good example of one is the oil light indicator in your automobile. Motor oil is constantly under pressure from the operation of your engine. When the amount of oil diminishes it also reduces the pressure inside the engine that the oil exerts. Once it reaches a certain, predetermined point that lack of pressure creates an electrical contact in the pressure switch which activates a warning light on your dashboard, indicating that you need to add oil to the engine. That's a pressure switch that caused the effect! There are generally two types of pressure switches, pneumatic or air pressure switches and hydraulic or liquid pressure switches. Both types of switches can be found in a wide variety of machinery from vehicles to water heaters to large factory boilers and equipment. The usefulness of pressure switches goes beyond the warning that you need to add oil to an engine. Pneumatic Pressure Switches These types of pressure switches can also be called air pressure switches or temperature switches as well depending on their use. Perhaps the most obvious example of a pneumatic pressure switch is the air pressure gauge used in aircraft that operated at high altitudes where the air pressure is much lower than on the ground. Once the air pressure in the cabin of the plane drops, the electronic switches light up a warning signal to the pilots indicating that there might be a leak of air pressure in the plane. Other examples include gas compressors that are switched off once a certain set pressure is reached and rechargeable batteries that reach their full capacity. Didn't know pressure switches were so important, did ya? Hydraulic Pressure Switches Hydraulic pressure switches are based on the pressure of liquids in a confined space. They can also be called water pressure switches, vacuum switches or high pressure switches depending on their use. Beyond indicating oil pressure, you have hydraulic pressure switches for your brakes, automatic transmissions and power steering. Inside bag filters in dust control systems which raise a warning if there is not enough pressure to correctly operate the device and used for water pipes to indicate the amount of pressure in the lines. The importance of pressure switches cannot be understated, although they are often taken for granted. Having your vehicle engine operating smoothly takes pressure switches that are functioning normally to indicate when potential problems may arise in your oil, transmission or brake fluid. Remember that if you are looking at many types of temperature gauges along with water and air pressure dials, then you are seeing pressure switches at work.