Hydraulic Pressure Switches
Pressure switches are devices that convert pressure changes into electrical or linear energy based on transducer activation. They can turn on due to pressure decrease or increase, depending on the application. The two main types of pressure switches are triggered by hydraulic or pneumatic pressure, and are available in either contact or non-contact versions. Contact means the unit is physically placed within the unit to gauge the pressure, while non-contact means the unit uses advanced technology to measure the pressure based on other types of sensors while remaining outside of the container. Hydraulic pressure switches are often used in automobiles to alert drivers of the vehicle’s fuel levels, but there are many other applications that utilize the pressure switch.
How Hydraulic Pressure Switches Work
Pressure switches are typically contact switches, meaning they fit into a container of liquid to measure pressure. Because most units are very small, the displacement of the unit is factored into the measurement. The unit is composed of two sections—the transducer unit and the switch unit. The transducer is the piece of equipment that measures the pressure in the container, and can be set to identify ascending pressure, descending pressure, or, in some models, multiple pressure points. When the set pressure is met, the transducer sends a signal to the switch unit, which converts that message into electrical energy. This energy triggers the next step in the application. In a fuel gauge, for instance, this electrical energy can be used to activate a warning light if the pressure gets too low. In rocketry, scientists can monitor pressure to prevent explosions. In petroleum mining, workers can learn if they are in danger of hitting an air pocket and creating an explosion.
Pressure switches are available with different settings and range functionality, so it is important to select the correct switch for an application. Some liquids are more viscous, and this can confuse certain basic switches if they are not properly attuned to the liquid type. However, most hydraulic pressure switches can handle the majority of hydraulic fluids. Hydraulic pressure switches are also designed to handle different pressure levels. A typical hydraulic pressure switch operates between 300-2600 PSI, although higher levels of 4000 PSI and even up to 12000 PSI are available at greater cost. Average temperature ranges are between -20 degress Fahrenheit and 160 degrees Fahrenheit.
Hydraulic Pressure Switch Applications
Automobiles feature many hydraulic pressure switches, although this is true of any piece of equipment or vehicle that relies on hydraulic fluids, including aerospace devices and many other motorized vehicles. The applications are as simple as activating a braking light after detecting a rise in pressure of brake pipes. In airplanes, these signals can be very important to the pilot, as he or she needs to constantly monitor hydraulic fluids that operate plane flaps, lights, landing gear, and various types of coolant throughout the craft. Rocket propulsion operates on directional pressure release, so these types of switches are very important in launching satellites and spacecraft. These situations are much more volatile than a simple braking light activation, as improper pressure monitoring can result in explosions.