Pressure Switches
A pressure switch operates an electrical contact to send an alarm signal when a certain set pressure has been reached on its input sensor.
Pressure switches are widely used to automatically supervise and control systems that use pressurized fluids. Examples include HVAC systems, well pumps, and furnaces. In industrial automation they analyze, monitor, and control deviations in the system caused by pressure rises. In the chemical process industry they are often used to protect positive-displacement pumps from over-pressurization. They are also increasingly installed between a rupture disc and SRV to monitor pressure build-up in the interspace. As they are wired directly to a control panel, they provide real-time information with no need to manually inspect the valve every shift.
Key Components of a Pressure Switch:
- The process connection, which must provide a leak-tight connection between the pressurized medium and the sensing element.
- The measuring elements, which comprise a sensor, a metal or rubber diaphragm that deforms under pressure, and an actuator, which translates the sensor’s movement into mechanical action.
- The switch contact, which opens or closes the electrical circuit.
- An adjustment mechanism or screw calibrates the switch so it activates at the desired pressure.
- The electrical terminals provide points for connecting the switch to an external circuit.
Pros:
- Simple
- • Rugged
- • Can withstand harsh environments
- • Suitable for a wide variety of applications
Cons:
- Can be difficult to calibrate
- May require recalibration over time
- May malfunction due to fluctuating fluid pressure
Pressure Transducers
A pressure transducer converts pressure into an electrical signal by physically deforming under pressure and measuring this deformation through electrical response.
Pressure transducers are integral for precise monitoring and control in industrial processes that involve fluids or gases. In process control, they are crucial for real-time pressure monitoring in pipelines and tanks, helping maintain system efficiencies across various industries such as oil and gas, pharmaceuticals, and food processing. In the automotive sector, they monitor fuel and oil pressures to ensure optimal engine performance. Aerospace applications are critical as well, including cabin pressure control and monitoring of hydraulic systems.
Key Components of a Pressure Transducer:
- The process connection ensures a secure, leak-proof seal between the pressurized medium and the transducer, typically using threaded, flange, or clamp fittings.
- The sensing element includes a piezoresistive sensor or capacitive sensor, which changes resistance or capacitance respectively under varying pressures.
- The diaphragm is a thin, flexible membrane that deforms under pressure, directly affecting the sensing element.
- The signal conditioning circuitry amplifies and converts the sensor output into a usable electrical signal, typically a voltage or current proportional to the pressure.
- The electrical output terminals provide points for electrical connectivity, allowing integration into broader monitoring or control systems.
Pros:
- Highly accurate
- Versatile
- Digital Integration for remote monitoring
Cons:
- More complex to design and manufacture
- Cost
- Sensitivity: May require frequent calibration and can be sensitive to environmental changes
OsecoElfab can provide pressure switches and transducers as part of larger rupture disc and burst sensor orders. Please contact our engineering team for more details.