
( Brand: Ask Mitsubishi ), ( Manufacturer Part Number: OPG-DU-R1/4-39-250 ), ( Part Type: Pressure ), ( Country Of Origin: Japan )
The **Mitsubishi OPG-DU-R1/4-39-250 Glycerin-Filled Pressure Gauge** is a high-precision, durable instrument designed for reliable monitoring of fluid pressure in industrial, automotive, and laboratory applications where accuracy and longevity are paramount. Engineered with Mitsubishi s reputation for quality and innovation, this gauge features a robust **1/4-inch NPT (National Pipe Thread) male connection**, ensuring secure and leak-proof installation in systems where space is limited but performance demands are high. The **glycerin-filled housing** provides superior protection against temperature fluctuations, corrosion, and mechanical shock, making it ideal for environments where traditional oil-filled gauges might fail under extreme conditions. With a **39-inch (990 mm) dial face**, this gauge offers ample visibility for readings, while the **250 psi (17.2 bar) maximum range** delivers precise measurements for applications requiring moderate to high-pressure monitoring, such as hydraulic systems, automotive brake testing, pneumatic equipment, and laboratory setups.
The gauge s **durable brass casing** and **stainless steel bourdon tube** ensure resistance to wear and tear, extending its operational lifespan even in demanding conditions. The **black enamel dial** is clearly marked with bold, easy-to-read graduations, allowing operators to quickly assess pressure levels with minimal ambiguity. Additionally, the **back-mounted connection** simplifies installation and maintenance, reducing downtime while ensuring a clean, unobstructed front panel for optimal visibility. Whether integrated into a hydraulic press, a test bench for automotive components, or a scientific apparatus requiring consistent pressure control, this gauge delivers the reliability and precision engineers and technicians depend on. Its compact yet sturdy design makes it a versatile choice for both new installations and retrofitting existing systems where space efficiency and performance are critical.
The **Mitsubishi OPG-DU-R1/4-39-250** is a glycerin-filled pressure gauge designed for use with hydraulic, pneumatic, or general industrial systems. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.
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### **Pros**
1. **Glycerin-Filled Design**
- The glycerin filling provides damping, reducing gauge oscillation and vibration errors. This makes readings more stable and accurate in dynamic systems (e.g., hydraulic presses, compressors, or fluctuating pressure environments).
- Glycerin is less volatile than mercury or oil, reducing the risk of leakage or contamination in the system.
2. **High Accuracy and Reliability**
- Mitsubishi is a reputable brand known for precision-engineered instruments. This gauge is likely calibrated to meet industry standards (e.g., ISO 2281, ANSI B40.100), ensuring consistent performance.
- The 1/4-inch NPT connection is standard for many industrial applications, making installation straightforward.
3. **Wide Pressure Range**
- The gauge measures up to **250 psi (17.2 bar)**, which is suitable for moderate to high-pressure systems (e.g., HVAC, automotive, or light industrial machinery). The 39-inch dial size provides clear visibility of pressure levels.
4. **Durable Construction**
- The metal housing and robust sealing are designed to withstand harsh environments, including temperature fluctuations and minor shock. Glycerin-filled gauges are generally more durable than dry gauges in cyclic or pulsating pressure applications.
5. **Compatibility with Various Fluids**
- Glycerin filling is non-corrosive to most metals and doesn t react with common hydraulic fluids (e.g., mineral oil, water-glycol mixtures), making it versatile for different systems.
6. **Easy Maintenance**
- Glycerin-filled gauges typically require less frequent recalibration than dry gauges in vibrating environments. The filling also helps protect the internal mechanism from dust and moisture.
7. **Cost-Effective for Industrial Use**
- While not the cheapest option, its longevity and accuracy often justify the investment in applications where gauge reliability is critical.
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### **Cons**
1. **Limited Pressure Range**
- At **250 psi**, this gauge is not suitable for high-pressure systems (e.g., heavy machinery, automotive brake systems, or compressed air above 300 psi). For such applications, a higher-range gauge (e.g., 600 psi or 1000 psi) would be necessary.
- The **1/4-inch NPT connection** may be too small for high-flow systems, risking clogging or pressure drop.
2. **Potential for Glycerin Leakage**
- Over time, the glycerin filling can degrade or leak, especially if the gauge is subjected to extreme temperatures or mechanical stress. Leakage can lead to inaccurate readings or internal damage.
- Unlike oil-filled gauges, glycerin is more viscous and may not self-seal as effectively if the gauge is damaged.
3. **Size and Installation Constraints**
- The **39-inch dial** is large and may not fit in space-constrained applications. While this provides better readability, it can be impractical for compact systems.
- The **1/4-inch NPT thread** is standard but may require adapters for certain systems. Over-tightening during installation can damage the gauge or connection.
4. **Calibration Requirements**
- Like all pressure gauges, this model will eventually require recalibration to maintain accuracy. Industrial environments with frequent pressure fluctuations may necessitate more frequent checks.
- Calibration costs should be factored into long-term ownership.
5. **Limited Temperature Range**
- While glycerin-filled gauges perform well in moderate temperatures, extreme cold or heat (e.g., above 120 F/50 C or below freezing) can affect glycerin viscosity and gauge performance. For extreme conditions, a specialized gauge (e.g., oil-filled or temperature-compensated) may be needed.
6. **Higher Cost Than Basic Gauges**
- Compared to simple dry gauges or oil-filled models, this glycerin-filled gauge is more expensive upfront. The added cost may not be justified for low-pressure or static applications where damping isn t critical.
7. **Potential for False Readings in Extreme Vibrations**
- While glycerin damping reduces oscillation, in **extreme vibration** (e.g., heavy machinery or seismic activity), the gauge may still exhibit some lag or error. For such cases, a **vibration-proof gauge** or remote sensing system may be preferable.
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### **Conclusion**
The **Mitsubishi OPG-DU-R1/4-39-250 glycerin-filled pressure gauge** is a well-engineered instrument ideal for applications requiring **stable, accurate pressure readings in moderately dynamic or vibrating environments**. Its glycerin filling provides damping benefits that improve reliability in systems where pressure fluctuations occur (e.g., HVAC, light industrial hydraulics, or pneumatic systems). The gauge s durability, compatibility with various fluids, and Mitsubishi s reputation for quality make it a strong choice for general industrial use.
However, it is **not suitable** for high-pressure applications (above 250 psi), extreme temperature environments, or systems where space is severely limited. Additionally, users must account for potential long-term maintenance (e.g., glycerin leakage, calibration) and the higher initial cost compared to simpler gauges.
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### **Recommendation**
**Buy this gauge if:**- You need a **reliable, damping-filled gauge** for a system with **moderate pressure (up to 250 psi)** and **some vibration or pulsation** (e.g., hydraulic presses, compressors, HVAC systems).
- Your application involves **hydraulic fluids, water-glycol mixtures, or clean air**, where glycerin compatibility is beneficial.
- You prioritize **accuracy and longevity** over cost and can accommodate the **39-inch dial size**.
- The **1/4-inch NPT connection** is compatible with your system, and you can ensure proper installation to avoid damage.
**Avoid this gauge if:**- Your system operates at **pressures above 250 psi** (consider a higher-range gauge, e.g., 600 psi or 1000 psi).
- You work in **extreme temperatures** (below freezing or above 120 F/50 C), where glycerin performance may degrade.
- Your application has **severe space constraints** or requires **frequent high-flow measurements** (a smaller or oil-filled gauge may be better).
- You are on a tight budget and can use a **dry or oil-filled gauge** for static or low-vibration systems.
**Alternatives to Consider:**- For **higher pressures**, opt for a **Mitsubishi OPG-DU-R1/4-600-250** or similar 600 psi gauge.
- For **extreme temperatures**, choose an **oil-filled gauge** (e.g., Mitsubishi OPG-DU-R1/4-39-250 with oil filling).
- For **compact installations**, look for a **smaller dial size** (e.g., 2.5-inch or 4-inch) with the same pressure range.
- For **high-vibration environments**, consider a **vibration-proof gauge** or a **remote sensing system** with a local indicator.
In summary, this gauge is a **solid choice for its intended use**, but its suitability depends on matching it to your specific system requirements. Always verify compatibility with your fluids, pressure range, and environmental conditions before purchasing.
Next day shipping available. ASK Mitsubishi OPG-DU-R1/4-39-250 Glycerin Filled Pressure Guage. New Old Stock. Un-used new condition.