Gauge pressure
Bourdon
A Bourdon tube converts pressure into mechanical movement to operate the microswitch. A typical solution for medium to high and high pressure ranges.
Mechanical pressure switching
Mechanical pressure switches
Dedicated instruments for ON/OFF pressure control through one or more electrical contacts. Selection starts with setpoint, deadband, maximum pressure, contacts, materials and hazardous-area or functional-safety requirements.
Multibrand supply:
we offer mechanical pressure switches from international and Italian manufacturers, including WIKA and Te.Ma Vasconi, without restricting the solution to one model. This page covers mechanical rather than electronic pressure switches.
Types
The mechanical sensor depends on the pressure range
Gauge pressure
Diaphragm
Diaphragm deflection operates the contact. Used across a wide pressure range, it may be preferred for sensitivity, robustness or specific wetted materials.
Low pressures
Capsule
Suitable for low positive and negative pressures, especially in gases, HVAC, ventilation and filtration.
ΔP
Differential
Compares two pressures and switches at the selected differential pressure. Typical applications include filter blockage, level, ventilation, pumps and heat exchangers.
Absolute pressure
Absolute
Operates relative to absolute vacuum, independently of atmospheric pressure changes. Useful for vacuum, gases, distillation and dedicated processes.
Selection guide
The setpoint alone is not enough
Key concepts
Setpoint, deadband and reset
Setpoint
The pressure threshold that changes the contact state. The scale or setting range must allow stable adjustment in the required operating region.
Deadband
After tripping, pressure normally needs to change by a certain amount before the contact returns to its original state. This differential prevents rapid switching around the threshold.
Hazardous areas and safety
ATEX, IECEx and SIL
Certifications depend on manufacturer, series and configuration.
Mechanical pressure switches are available for potentially explosive atmospheres, depending on series and protection method.
International projects may require IECEx certification, sometimes combined with ATEX within the same family.
For safety functions, we select specifically suitable, certified configurations and check the required SIL level.
ATEXIECExEx iaEx dSILIEC 61508
Comparison
Pressure switch or gauge with contacts?
Pressure switch
Its primary function is switching. Prefer it when a dedicated enclosure, reliable setpoint, switching capability, hazardous-area suitability or safety function is required.
Gauge with contacts
Its primary function remains local indication, with one or more additional alarm or control contacts.
Multibrand replacements
Replacing an older pressure switch
The pressure range alone is insufficient for replacement. Send us a photograph or nameplate, setpoint, deadband, maximum pressure, contacts, wetted materials, connection and certifications. We can propose an equivalent from WIKA, Te.Ma Vasconi or another manufacturer.
Request a quotation
Pressure switch configuration
For safety or Ex applications, attach the customer specification if available.
FAQ
Mechanical pressure switch FAQ
What is the difference between a pressure switch and a transmitter?
A mechanical pressure switch changes a contact state at a threshold. A transmitter sends a continuous measurement to the control system.
What is the difference between setpoint and deadband?
The setpoint is the pressure at which the contact changes state. Deadband is the difference between trip and reset pressures.
When is a Bourdon pressure switch used?
Normally for medium to high and high pressure ranges, where Bourdon-tube deflection operates the microswitch.
When is a diaphragm pressure switch useful?
It suits low to medium-high ranges and may offer greater sensitivity or compatibility with particular process conditions, depending on construction.
When is a capsule pressure switch required?
Mainly for low positive or negative pressures, typically in gases, HVAC, ventilation and filtration.
What is a differential pressure switch used for?
It operates when the pressure difference between two points reaches a threshold, for example for filter blockage, level, ventilation, pumps or heat exchangers.
Are ATEX, IECEx and SIL mechanical pressure switches available?
Yes. Depending on manufacturer and series, ATEX and IECEx configurations are available, including Ex ia or Ex d versions, as well as switches suitable for SIL functional-safety applications. Certification must be verified for the specific configuration.
Does a mechanical pressure switch need power?
The mechanical sensing element needs no power to detect pressure. Its electrical contact is connected to the plant's specified control or power circuit.