The Ultimate Guide to Rear Mount Pressure Gauges: Selection, Installation, and Maintenance
In the world of industrial instrumentation, precision and reliability are non-negotiable. For applications where panel space is limited or where direct front-mounting isn’t feasible, a rear mount pressure gauge offers an ingenious solution. This comprehensive guide will walk you through everything you need to know about selecting, installing, and maintaining these essential tools.
What is a Rear Mount Pressure Gauge?
Unlike traditional gauges mounted from the front, a Rear Mount Pressure Gauge is installed from the back of the panel. The connection (stem) protrudes through a hole, and the gauge is secured from the rear using a nut or a special clamp. This design provides a clean, flush front appearance and is ideal for control panels, machinery, and enclosures with restricted front access.
Key Advantages and Applications
The primary benefit is space-saving and a secure, vandal-resistant installation. They are widely used in hydraulic systems, process control panels, OEM equipment, and compressor units. Their streamlined profile minimizes the risk of accidental impact damage from the front.
How to Select the Right Gauge
Choosing the correct gauge is critical for performance and safety. Consider these factors:
Pressure Range: Select a gauge where the normal operating pressure is at 50-75% of the full-scale range.
Connection Size and Type: Ensure the stem thread (e.g., 1/4″ NPT, 1/2″ NPT) matches your panel hole and piping.
Dial Size and Accuracy: Common sizes are 2″, 2.5″, and 4″. Higher accuracy classes (e.g., ASME B40.1 Grade 1A) are needed for critical measurements.
Case and Window Material: Choose stainless steel for corrosive environments and polycarbonate windows for high impact resistance.
Understanding Glycerin Filling
For applications with significant vibration or pulsation, a glycerin-filled rear mount gauge is highly recommended. The viscous fluid dampens needle movement, preventing wear and ensuring easy, stable readings.
Step-by-Step Installation Guide
Proper installation ensures accuracy and longevity.
1. Prepare the Panel: Drill a clean hole to the exact specified diameter for the gauge stem.
2. Insert the Gauge: Pass the stem through the panel from the front.
3. Secure from the Rear: Thread the provided locknut onto the stem from behind the panel and tighten securely. Avoid over-tightening, which can distort the case.
4. Make the Pressure Connection: Connect your pressure source to the gauge’s process port, using appropriate sealant on the threads.
Essential Maintenance Tips
Regular maintenance prevents failure. Inspect the gauge periodically for signs of damage, moisture ingress, or needle sticking. Calibrate it annually against a known standard. For liquid-filled gauges, check for fluid clarity and leaks. Always depressurize the system before attempting any maintenance or removal.
