A Pressure Switch is a simple electromechanical device designed to monitor the pressure of a fluid (liquid or gas) and automatically open or close an electrical contact when a pre-set pressure level is reached. It acts as a vital safety sentinel and control point in a system, converting a physical pressure value into an electrical signal that can be used to activate alarms, shutdown sequences, or control other equipment like pumps, compressors, and actuators.

The core function of a pressure switch is to provide automatic control based on pressure.

• Safety Shutdown: Protects equipment from damage due to over-pressure or under-pressure conditions (e.g., shutting down a compressor if pressure gets too high).
• System Control: Automatically starts or stops motors, pumps, or alarms based on preset pressure thresholds.
• Monitoring & Alarm: Provides a warning signal to an operator or control system if pressure deviates from a normal operating range.

Most pressure switches operate on a balance-of-forces principle:

1. Pressure Sensing: A piston, diaphragm, or bellows is exposed to the system pressure.
2. Force Generation: The pressure creates a force that acts against a pre-tensed spring (the set point adjustment).
3. Actuation: When the pressure force overcomes the spring force, it mechanically moves a switching mechanism.
4. Electrical Signal Change: This movement instantly opens or closes one or more electrical contacts within the switch.
5. Reset: When pressure returns to a normal level, the spring force moves the mechanism back, resetting the electrical contacts to their original state.

The pressure at which the switch changes state is called its set point.

• Pressure Range: The minimum and maximum pressures the switch can sense (e.g., 0-100 PSI, 500-5000 PSI).
• Set Point Accuracy: How closely the switch activates to the desired set point (e.g., ±1% of range).
• Electrical Rating: The voltage and current (AC or DC) the switch contacts can handle (e.g., 120VAC, 15A / 24VDC, 5A).
• Switch Function: Normally Open (NO) or Normally Closed (NC) contacts.
• Port Size & Connection: Thread size for process connection (e.g., ¼" NPT, G¼).
• Wetted Materials: Materials that contact the media (e.g., 316SS, Brass, Buna-N). Must be compatible with the fluid.
• Enclosure Rating: IP65 (dust-tight and protected against water jets), NEMA 4X (weatherproof & corrosion-resistant).

Pressure switches are ubiquitous across all industries:

• HVAC: Controlling compressor operation, fan activation, and proving air flow.
• Industrial Machinery: Hydraulic and lubrication system control, over-pressure protection.
• Water & Wastewater: Pump control, tank level by pressure, filter monitoring.
• Power Generation: Monitoring lube oil pressure, boiler pressure, and auxiliary systems.
• Mobile Equipment: Monitoring hydraulic pressure, brake air pressure, and implement control.
• Compressed Air: Controlling air compressor operation and monitoring for leaks.

• Proven Reliability: Built with industrial-grade materials and tested for millions of cycles, ensuring long-term performance.
• Precision & Repeatability: Consistent actuation at the set point for stable system control and safety.
• Media Compatibility Expertise: We help you select the right wetted materials for your specific fluid, preventing premature failure.
• Easy Installation & Adjustment: Clear calibration scales and accessible adjustment mechanisms simplify setup.
• Global Certification & Support: Our switches meet international standards (CE, UL), and our technical team provides expert application support.

To select the correct pressure switch, please provide:

• Function: (e.g., High-Pressure Cut-Out, Low-Pressure Alarm, Pump Control)
• Desired Set Point(s): (e.g., Cut-Out at 150 PSI, Cut-In at 100 PSI)
• System Media: (e.g., Hydraulic Oil, Compressed Air, Water)
• Pressure Range: (Maximum pressure expected in the system)
• Electrical Requirements: (Voltage, Current, AC/DC, NO/NC contact preference)
• Process Connection: (Port size and thread type)
• Environmental Conditions: (Hazardous area, washdown, etc.)