What is a pressure gauge?
Pressure gauges are pressure measuring devices that record and display the pressure of liquids or gases. They are indispensable in hydraulic and pneumatic systems as they visualise the current operating pressure and thus enable safety, efficiency and precise control.
The most widely used type is the Bourdon tube pressure gauge, which is characterised by its simple, robust and reliable design. It has been a standard in pressure measurement technology for decades. Bourdon tube pressure gauges provide a direct and immediate pressure indication, which makes them particularly valuable for maintenance, servicing and test benches.
Types and standards
Pressure gauges differ in design and measuring principle. There are different types for different pressures and applications, each offering certain advantages. These include
Analogue Bourdon tube pressure gauges: Classic design, usually C-shaped or helically bent spring, according to EN 837-1.
Diaphragm and capsule pressure gauges: For low pressures, vacuum or pulsating systems, according to EN 837-3.
Differential pressure gauge: Measures the pressure difference between two points.
Digital pressure gauges: Electronic versions, based on sensors, not on Bourdon tube technology, and not covered by EN 837-1.
The different standards ensure that the devices are reliable and compatible in their area of application. Bourdon tube pressure gauges comply with EN 837-1, while other types comply with their own standards.
Areas of application
Bourdon tube pressure gauges are versatile and can be used to monitor operating pressures, diagnose faults and safeguard systems. Typical areas of application are
Hydraulic systems: Monitoring of operating pressures in machines, units and systems.
Pneumatics: Pressure control; for pulsating systems only useful with damping (e.g. glycerine filling).
Test benches: development and quality assurance.
Mobile hydraulics: agricultural and construction machinery, commercial vehicles.
Building technology: heating and air conditioning systems, water and gas pipes.
OEM original equipment: Bourdon tube pressure gauges are installed directly in machines due to their favourable price and robust design.
Limitations:
Not suitable for very low pressures (< 0.6 bar) or vacuum; capsule or diaphragm pressure gauges are often used here.
How does a Bourdon tube pressure gauge work?
The Bourdon tube pressure gauge works according to a mechanical principle. The centrepiece is a C-shaped or spirally bent metal spring (Bourdon spring), which deforms as the pressure increases. This movement is transmitted via a linkage to a pointer which indicates the pressure on a scale.
The advantages of this principle are
Mechanical measuring principle, no current or energy required.
Robust and durable.
Easy to read at stable pressures; ideally glycerine-filled at pulsating pressures.
Bourdon tube pressure gauges are reliable in standard applications; digital pressure sensors or pressure balances are used for laboratory or high-precision measurements.
Bourdon tube pressure gauges from STAUFF
We offer a wide range of Bourdon tube pressure gauges that are specially optimised for use in hydraulic systems. Our products are characterised by their durability, precision and flexibility.
Analogue Bourdon tube pressure gauges (type SPG)
Measuring ranges up to 1000 bar
Housing sizes: 63 mm and 100 mm
Stainless steel housing for maximum robustness
Glycerine-filled for damping pressure surges
Scales in bar, PSI and on request also in other units (e.g. kPa)
Various connection threads: BSP, NPT, SAE
Test kits
Complete sets with Bourdon tube pressure gauges, measuring hoses and adaptors
Ideal for mobile measurements and test bench applications
These kits contain all the accessories required for safe and flexible measurement. The combination of pressure gauge and accessories makes handling easier and ensures precise results.
Accessories for pressure gauges
The accessories increase the functionality of the pressure gauges and ensure safe use:
Shut-off valves with relief (used as protective valves)
Pressure gauge selector switch for switching between measuring points
Connection adapters and screw fittings
Measuring hoses for measurements at a distance from the measuring point
Mounting brackets and rings for stable mounting
Rubber protective caps to protect the housing
These components make installation and handling of the pressure gauges considerably easier and enable precise measurements under different operating conditions.
Advantages of STAUFF products
Bourdon tube pressure gauges always offer robust and reliable measurements at stable pressures. They are versatile and can be mounted flexibly.
Robust design: Stainless steel housing (1.4301) and precision manufacturing ensure a long service life. Corrosion-resistant for oil and gas applications.
Glycerine filling: Hose spring and pointer are filled, which dampens shocks and vibrations and improves measuring accuracy
Wide pressure range: Measuring ranges up to 1000 bar cover most industrial requirements.
Double scale: Double display, for example in bar and PSI, enables international use and avoids conversion errors.
Customisable: Scales in bar, PSI and, on request, in other units (e.g. kPa) possible, as well as simple implementation as a private label with customer logo on the scale plate
Versatile connections: Selection of BSP, NPT and SAE threads facilitates integration into existing systems.
Accessories & service: STAUFF offers suitable brackets, adaptors and professional advice - fast delivery included.
STAUFF complements these features with tested materials, a wide range of measuring ranges, various housing sizes and matching accessories. Customers benefit from complete test sets, customisation options and durable products.
Selection criteria
The following points should be considered when selecting a suitable pressure gauge:
Measuring range: Suitable for the system pressure.
Media compatibility: Material must be compatible with the hydraulic fluid.
Accuracy: Bourdon tube pressure gauges are robust; select other types for high-precision measurements.
Connection type: BSP, NPT, SAE.
Mounting type: Front or panel mounting.
Standards: EN 837-1 for Bourdon tube pressure gauges; other types have their own standards.
Careful selection ensures that the pressure gauge works reliably and has a long service life.
FAQs
What does a pressure gauge do and what is it used for?
What standards apply to Bourdon tube pressure gauges?
Bourdon tube pressure gauges comply with the EN 837-1 standard, while other types, such as diaphragm or capsule pressure gauges, have their own standards (e.g. EN 837-3).
What pressure ranges do STAUFF Bourdon tube pressure gauges cover?
Depending on the version, our Bourdon tube pressure gauges are available for pressure ranges up to 1000 bar.
Are Bourdon tube pressure gauges always glycerine-filled?
No, not all pressure gauges. However, all STAUFF Bourdon tube pressure gauges are filled with glycerine to dampen large pressure surges.
Why are some Bourdon tube pressure gauges filled with glycerine?
The liquid dampens pressure surges, stabilises the display and extends the service life of the device.
What connection types do STAUFF Bourdon tube pressure gauges offer?
We offer common connection types such as BSP (G), NPT and UNF/SAE.
Where are STAUFF Bourdon tube pressure gauges mainly used?
Our pressure gauges are used in hydraulic and pneumatic systems, test benches, industrial plants, in mechanical engineering and in mobile machines such as agricultural or construction machinery. They are used both in maintenance and in OEM original equipment.
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