Diaphragm Pressure Gauges: Precision Measurement for Challenging Applications

Key Advantages of Chemical Seal Pressure Gauges

Superior Performance in Low Pressure Applications

Unlike standard bourdon tube gauge designs, diaphragm gauges offer highly accurate measurements in low-pressure conditions, often measuring reliably in the mbar range where traditional pressure gauges struggle. The diaphragm’s sensitive and responsive design, with its larger surface area, ensures precision in measurements even at minimal pressure differentials, making these gauges ideal for specialised industrial processes where bourdon tube technology is inadequate.

Excellent Resistance to Corrosive and Aggressive Media

Diaphragm pressure gauges (also known as Diaphragm seal systems) deliver reliable performance in environments with corrosive chemicals or aggressive media due to their robust construction and flexible diaphragm materials. While standard bourdon tube pressure gauges may deteriorate quickly, the diaphragm can be manufactured from resistant materials such as Hastelloy or PTFE. This makes diaphragm gauges especially suited to chemical or petrochemical industries where pressure monitoring of aggressive liquids is common.

Optimal for Sanitary and Hygienic Conditions

PCI Instrument gauges are preferred in sanitary applications due to their easy-to-clean design and minimal contamination risks. Their construction reduces the likelihood of process fluid build-up within the pressure instrumentation, thus enhancing safety and hygiene. Many designs incorporate a diaphragm seal that prevents the measured medium from entering the gauge mechanism, particularly important when handling viscous or dangerous substances.

Industry Applications for Pressure Gauge with Diaphragm Seal

Process Industry and Petrochemical Applications

Diaphragm gauges withstand highly corrosive media common in process industry settings and petrochemical refineries. These deliver stable, accurate measurements essential for process safety and control, often outperforming standard bourdon tube technology in these demanding environments.

Pharmaceutical, Food & Beverage Industries

Due to their design and construction, Hygienic diaphragm pressure gauges are ideal for applications where contamination risks must be minimised. The smooth diaphragm surface prevents product accumulation, and specialised weld techniques ensure no contamination occurs. These gauges meet stringent industry requirements, including compliance with sanitary standards that bourdon tube gauge designs often cannot satisfy.

Power Generation and High Pressure Applications

In environments demanding the highest reliability and safety standards, diaphragm pressure gauges provide invaluable service. Their robust construction, often featuring a corrugated diaphragm for improved sensitivity, ensures accurate pressure measurement under severe conditions. For extremely high pressure applications, specialised diaphragm seals can be employed to protect the unit while maintaining measurement accuracy.

Choosing the Right Diaphragm Pressure Gauge

When selecting a diaphragm gauge, several key factors should be considered:

• Pressure Range: Match the gauge’s range closely to the expected operating pressures to ensure accuracy, whether measuring in psi, mbar, or other units.
• Material Selection: Ensure diaphragm materials are chemically compatible with your media to avoid premature corrosion or degradation.
• Connection Types: Select the appropriate threaded or flanged chemical seal for your specific installation requirements. Thread options and flange designs vary based on the application. For assistance, refer to our guide on Choosing the Right Diaphragm Seal Size.
• Upper Housing Design: Consider the upper housing construction to ensure compatibility with your environmental conditions.

Maintenance and Calibration

Regular maintenance and calibration are essential to maintain diaphragm gauge accuracy:

• Regular Calibration: Scheduled calibration helps maintain precision and reliability of the pressure gauge. For calibration procedures and frequency recommendations, explore our Instrument Repair and Calibration Services.
• Cleaning and Handling: Properly clean and handle diaphragm pressure gauges to ensure consistent performance and avoid accidental diaphragm damage.

For further insights into calibration and industry standards, you may refer to the authoritative guidance provided by the British Measurement and Testing Association (BMTA).

Diaphragm Seal Systems: Frequently Asked Questions

How do diaphragm pressure gauges differ from bourdon tube gauges?

While bourdon tube gauges use a curved tube that straightens under pressure, diaphragm pressure gauges utilise a flexible membrane that deflects with pressure changes, offering greater sensitivity, especially at low pressure ranges.

What is the typical lifespan of a sealed diaphragm pressure gauge?

With proper maintenance, diaphragm pressure elements can offer reliable performance for many years. The lifespan typically depends on the severity of operating conditions and maintenance practices.

Are diaphragm gauges suitable for high industrial pressure applications?

While diaphragm pressure gauges excel in low-to-medium pressures, for extremely high atmospheric pressure applications, specialised diaphragm seals or reinforced diaphragm designs may be required for optimum performance.