Differential pressure switches

Key Features and Functions:

1. Pressure Sensing Elements: Differential pressure switches incorporate pressure sensing elements such as diaphragms, bellows, or bourdon tubes that respond to changes in pressure between two input ports or pressure sources. When the pressure differential exceeds a setpoint threshold, the sensing element activates the switch mechanism to open or close electrical contacts.
2. Setpoint Adjustment: Most differential pressure switches allow for manual adjustment of the setpoint or switching pressure threshold using adjustable screw mechanisms or calibration knobs. This feature enables users to customize the switch’s operation based on specific system requirements and desired pressure differentials.
3. Switching Action: Differential pressure switches are available in various switching configurations, including SPDT (Single Pole, Double Throw), DPDT (Double Pole, Double Throw), and SPST (Single Pole, Single Throw). The switch contacts can be normally open (NO), normally closed (NC), or changeover (CO), providing flexibility for different control and monitoring applications.
4. Pressure Ranges: These switches are designed to accommodate a wide range of pressure differentials, from low-pressure differentials (inches of water column) to high-pressure differentials (psi or bar), depending on the specific application and system requirements. Pressure ranges may vary based on the model and intended use of the switch.
5. Hysteresis or Deadband: Differential pressure switches often feature an adjustable hysteresis or deadband setting, which determines the difference between the switch’s activation and deactivation pressures. Hysteresis prevents rapid cycling of the switch due to minor pressure fluctuations around the setpoint, ensuring stable and reliable operation.
6. Enclosure and Housing: Differential pressure switches are housed in rugged enclosures or housings constructed from materials such as stainless steel, aluminum, or thermoplastics to withstand harsh operating environments, including temperature extremes, moisture, and chemical exposure. Weatherproof and explosion-proof enclosures are available for hazardous or outdoor installations.
7. Electrical Connections: These switches feature electrical terminals or connectors for easy wiring to control circuits, alarms, indicators, or PLCs (Programmable Logic Controllers). Terminal options include screw terminals, quick-connect terminals, or DIN rail mounting for convenient installation and integration into control systems.
8. Optional Features: Depending on the application, differential pressure switches may offer additional features such as integral pressure gauges, visual indicators (LEDs), test buttons for manual operation, and adjustable time delays for delayed switch response.