Pressure Switches
Pressure switches monitor system pressure and trigger actions like activating or deactivating equipment when preset thresholds are met, and they maintain safety by preventing overpressure or underpressure in hydraulic, pneumatic, and process systems to protect equipment and ensure reliable operation.
Mechanical pressure switches are electromechanical devices designed to sense fluid pressure and activate an electric circuit when a preset pressure threshold is reached. They typically employ a spring-loaded diaphragm or piston as the sensing element; when the process pressure overcomes the spring force at the set point, the mechanism moves to open or close a microswitch contact. This purely mechanical actuation means no external power is required for operation, which enhances their reliability and fail-safe characteristics. Mechanical switches remain a staple in industrial automation due to their robust construction, repeatable performance, and cost-efficiency.
Modern designs offer consistent set-point accuracy (often about ±1% of full-scale range), ensuring reliable and precise triggering at the desired pressure.
In industrial settings, these switches are valued for accuracy in control, high reliability, and safety assurance. They provide simple on/off control to maintain process pressures within desired limits and will repeatedly actuate at the calibrated setpoint under varying conditions.
Because of their ruggedness and long-term stability, mechanical pressure switches excel in harsh environments (vibration, extreme temperatures, etc.) where electronic sensors might falter. Crucially, they serve as safety interlocks – if system pressure strays outside safe limits or if power/primary sensors fail, the mechanical switch will directly shut down equipment or trigger alarms, preventing damage and ensuring safe operation.
Typical applications of mechanical pressure switches include:
Maintaining System Pressure
Automatically cycling pumps or compressors on/off to keep pressure within a specified range.
Overpressure and Underpressure Protection
Shutting down boilers, hydraulic presses, or gas compressors when pressure exceeds or drops below safe thresholds, thereby protecting equipment from damage.
Industrial Process Monitoring
Widely deployed across oil & gas, chemical processing, water treatment, HVAC and other sectors for critical pressure monitoring and control tasks (e.g. controlling burners, guarding pipelines, and activating alarms).
Mechanical pressure switches are accurate, reliable controllers and safeguards in process control systems. Their straightforward mechanical operation and proven durability ensure consistent performance, contributing significantly to operational safety and optimal system performance by reacting promptly to pressure changes and keeping processes within design limits.
