The Ultimate Guide to Rear Mount Pressure Gauges: Selection, Installation, and Maintenance
In the world of industrial instrumentation, selecting the right pressure gauge is critical for safety, accuracy, and longevity. Among the various mounting configurations available, the rear mount pressure gauge stands out for its unique advantages in specific applications. This comprehensive guide will walk you through everything you need to know about these essential tools.
What is a Rear Mount Pressure Gauge?
A rear mount pressure gauge is characterized by its connection point located directly on the back of the instrument’s case, as opposed to the lower (bottom) connection. This design allows the gauge to be mounted flush against a panel, dashboard, or wall, saving space and providing a clean, integrated look. The process connection, typically a threaded male or female NPT, protrudes from the rear for direct piping.
Key Advantages and Typical Applications
The primary benefit of a Rear Mount Pressure Gauge is its space-saving panel mounting capability. This makes it ideal for control panels, hydraulic power units, compressor skids, and machinery where front-facing access is paramount and cabinet space is limited. Its streamlined design also reduces the risk of snagging on external objects.
How to Select the Right Rear Mount Gauge
Choosing the correct gauge involves several key factors beyond just the mounting style.
Pressure Range, Media, and Case Material
Always select a gauge with a range where the normal operating pressure falls at 50-75% of the scale. Consider the media (gas, oil, water, corrosive chemicals) to choose compatible wetted parts like brass, stainless steel, or Monel. The case material (stainless steel, plastic, or phenolic) should suit the environmental conditions (humidity, corrosion, explosive atmospheres).
Dial Size and Accuracy Class
Dial size (e.g., 2″, 4″, 6″) affects readability from a distance. Accuracy classes (ASME B40.1 Grade B, 1.0%, 0.5%) determine precision; critical processes require higher accuracy. Don’t forget the unit of measure (PSI, Bar, kPa) needed for your operators.
Step-by-Step Installation Best Practices
Proper installation is crucial for performance and safety.
1. Shut Down & Depressurize: Always isolate and bleed the system before installation.
2. Use a Sealant: Apply appropriate thread sealant (e.g., Teflon tape) to the male threads, avoiding the first two threads to prevent contamination.
3. Mounting: Secure the gauge through its front flange holes onto a clean, flat panel surface. Avoid using the pressure connection to support or twist the gauge; hand-tighten the connection, then use a wrench on the wrench flats (if provided), not the case.
4. Pressure Pulsation & Vibration: For pulsating or vibrating systems, install a snubber or liquid-filled gauge to protect the internal movement and ensure a stable reading.
Essential Maintenance and Calibration
Regular maintenance ensures reliability. Periodically check for signs of damage, leaks, or fogging in liquid-filled gauges. Verify the
