Differential Pressure Switches

Mechanical differential pressure switches were developed to switch an electrical contact when the difference between two pressure values ​​in the process exceeds defined limits. The pressure difference may be too high or too low. Differential pressure switches do not have a sensitive local indicator, an analog output signal and do not require an electrical power supply. These simple devices are optimized to guarantee excellent repeatability and reliability of the switching behavior.

Differential pressure switches, which do not require a power supply, are used in safety-critical applications. Bourdon is a well-known supplier of equipment for power plants and offers a wide range of products specifically for nuclear power plants.

But many other applications, such as monitoring filters, levels in closed tanks, compressors, also benefit from this safe and simple solution.

Differential pressure switches are available in EEx ia and EEx d versions for hazardous areas. When combined with diaphragm seals, it can also be used in applications with critical process fluids or in hygienic installations in food or pharmaceutical production.

The Bourdon range of differential pressure switches offers reliability and proven durability against harsh environments and processes.

Bourdon pressure switches can be custom-made to suit your application requirements. You can choose from the full range below:

• Pressure ranges from -2.5…2.5 mbar to 2.5…30 ​​bar
• Maximum 220 bar static pressure
• Factory-set or customer-specified set point
• Fixed or adjustable dead band
• Different types of microswitches according to application
• Excellent repeatability of 1%
• Intrinsically safe (EEx ia) version for zones 0, 1, 2
• Explosion proof (EEx d) version for zones 1, 2, 21, 22
• Approvals for nuclear power plants

Mechanical Bourdon differential pressure switches are designed for alarm setting when pressure difference limits are exceeded.

Depending on the pressure range, the sensing element can be a membrane, piston or bellows. The sensing element is pressurized on two sides and works against the adjustable force of an internal spring.

The deflection of the sensing element activates a mechanical microswitch. The value of the set point is determined by the broadcast setting and can be set at the factory or by the customer. In some types of microswitches, the deadband can also be adjusted. This allows the set point and reset point to be defined separately.

Bourdon differential pressure switches offer excellent repeatability in a compact design. Its working principle is completely mechanical and does not require an electrical power source. Wiring is only required for reading microswitches.