Hydraulic Pressure Gauge Selection Guide: Dry or Glycerin Filled?

Choosing the right hydraulic pressure gauge involves more than simply matching the pressure range. Operating pressure, vibration, pressure pulsation, dial size, connection type, and material selection should all be considered before choosing a gauge. For hydraulic systems exposed to vibration and pressure fluctuations, gauge selection becomes particularly important. Glycerin-filled gauges are commonly used in these conditions because the liquid helps damp pointer movement and improves readability. Manogauge What Is a Dry Pressure Gauge? A dry pressure gauge has no liquid filling inside its case. It is commonly used in applications where vibration and pressure pulsation are limited. For stable systems, a dry gauge can provide a simple and practical pressure indication. However, applications with significant vibration or pulsation may require a liquid-filled design. Hidroteknik What Is a Glycerin-Filled Pressure Gauge? A glycerin-filled pressure gauge contains liquid inside the case surrounding the internal mechanism. The glycerin helps damp pointer movement caused by vibration and pressure pulsation. This makes the gauge easier to read and can reduce the mechanical effects of continuous vibration on the movement. IndustryInsights How Should You Choose the Pressure Range? The normal operating pressure should not remain close to the maximum scale of the gauge. A common selection approach is to keep normal operating pressure within approximately 25% to 75% of the gauge's full-scale range, while also considering pressure spikes and the actual operating conditions of the system. Manogauge For example, a hydraulic system operating around 200 bar should generally be evaluated with a gauge range that provides sufficient room above the normal operating pressure. Choosing the Right Dial Size Dial size affects readability. Smaller gauges are useful where installation space is limited, while larger dial sizes are generally easier to read from a distance and are often used on panels and industrial equipment. Manogauge Connection and Thread Selection The gauge connection must match the existing connection on the hydraulic system. Common sizes include 1/4 and 1/2 connections, but the thread standard must also be confirmed. A matching diameter alone does not guarantee compatibility, so always verify both the thread type and size before installation. Hidroteknik Brass or Stainless Steel? Material selection depends on the application and the measured medium. Stainless steel construction can be useful in environments where corrosion resistance is important. The wetted materials should also be compatible with the process medium to avoid corrosion and premature component failure. Manogauge Final Checklist Before selecting a hydraulic pressure gauge, check: - Normal operating pressure - Maximum system pressure - Pressure pulsation and vibration - Dry or glycerin-filled construction - Dial size - Thread type and size - Case and wetted-part materials - Installation environment Choosing the gauge according to the actual operating conditions helps provide clearer pressure readings and more appropriate instrument performance.