Digital pressure gauge installed on a pressure test bench

Pressure Switches

A pressure switch is a control device that automatically starts or stops equipment based on pressure changes. When the system pressure reaches a preset value, the internal contact mechanism automatically switches and outputs a signal to control pumps, air compressors, valves, or alarm systems. It is widely used in industrial automation and equipment protection applications.

Pressure Switches FAQ

Questions for mechanical and differential pressure switches used in automation and equipment protection.

What is the difference between a pressure switch and a pressure transmitter?
A pressure switch changes electrical state at a preset pressure for control or alarm. A pressure transmitter continuously outputs a pressure signal such as 4-20mA. Use a switch for on/off control and a transmitter for continuous monitoring.
Where are mechanical pressure switches commonly used?
Mechanical pressure switches are used for air, water, pumps, compressors, HVAC systems, and equipment protection. They are simple, direct, and useful when an on/off signal is enough.
When should a differential pressure switch be selected?
A differential pressure switch is selected when control depends on the pressure difference between two points, such as filter blockage, fan/duct pressure, clean rooms, or low differential pressure gas systems.
What should be checked before selecting a pressure switch?
Confirm pressure range, switch point, reset behavior, media type, electrical rating, connection type, enclosure protection, and whether the application has vibration, corrosive media, or hazardous-area requirements.
  • SJ Gauge differential pressure switch with Pascal scale
    Model: PRSMD

    Differential Pressure Switch

    • Easy installation and no power supply needed
    • Easily set the differential pressure switch values on the site
    • Limited to non-flammable and non-corrosive gases
    • Usually used in filter, fan, and duct pressure monitoring in building automation systems in the HVAC
  • SJ Gauge MPS compact mini pressure switch
    Model: MPS

    Mechanical Pressure Switch, Compact

    • Automatically resetting switch design
    • Wide pressure range, apply to multi work situation
    • Application to air、water pressure control, Indoor air conditioner system or more…