NOSHOK 25-500-30-VAC-MCMASTER Glycerin Filled Vacuum Gauge 1/4NPT 2.5 B589

( Brand: Noshok ), ( Manufacturer Part Number: 25-500-30-VAC-MCMASTER ), ( Part Type: Vacuum Gauge ), ( Connection Diameter: 1/4 In ), ( Country Of Origin: Poland )

Review NOSHOK 1/4npt 2.5 Inch Glycerin Filled Vacuum Gauge

The **McMaster-Carr Noshok 25-500-30-VAC 1/4 NPT Glycerin-Filled Vacuum Gauge (Part #B589)** is a precision-engineered instrument designed for reliable and accurate measurement of vacuum levels in industrial, laboratory, and HVAC applications. This high-quality gauge features a robust **1/4-inch National Pipe Thread (NPT) male connection**, ensuring a secure and leak-proof fit to your vacuum system, whether it s a refrigeration unit, a laboratory setup, or an air conditioning system. The **glycerin-filled design** provides superior damping and stability compared to traditional mercury or air-filled gauges, eliminating erratic needle movement and delivering smoother, more consistent readings. This feature is particularly advantageous in applications where rapid pressure fluctuations could otherwise compromise measurement accuracy.

With a **full-scale range of 25 to 500 inches of mercury (Hg) vacuum**, this gauge is well-suited for monitoring moderate to high vacuum levels, making it ideal for systems requiring precise control of air pressure, such as refrigeration compressors, vacuum pumps, or HVAC diagnostics. The **durable brass casing** and reinforced dial offer long-term reliability, while the **clear, easy-to-read scale** ensures quick and accurate interpretation of vacuum levels. The gauge s **backlit or illuminated dial option** (depending on model variant) enhances visibility in low-light environments, reducing operator fatigue and improving safety in industrial settings. Additionally, the **sealed construction** protects internal components from contamination, moisture, and temperature fluctuations, extending the gauge s operational lifespan.

Built to withstand the demands of professional use, the Noshok 25-500-30-VAC is constructed with **high-grade materials** that meet strict industry standards for performance and durability. Its **compact yet sturdy design** allows for easy installation in tight spaces, while the **quick-connect NPT fitting** simplifies integration into existing vacuum systems without the need for complex fittings or additional tools. Whether used for routine maintenance, troubleshooting, or critical process monitoring, this vacuum gauge provides engineers, technicians, and operators with the confidence of **precise, dependable measurements** ensuring optimal system performance and efficiency.

The **McMaster-Carr 25-500-30 VAC Glycerin-Filled Vacuum Gauge (B589)** is a 1/4 NPT threaded, analog vacuum gauge designed for measuring low-pressure systems. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

---

### **Pros**

1. **Glycerin-Filled Design**

- The glycerin filling prevents moisture and oil from damaging the internal mechanism, making it more durable in humid or oily environments compared to standard mercury or oil-filled gauges.

- Extends the gauge s lifespan by reducing corrosion and contamination risks.

2. **Wide Pressure Range (25 500 VAC)**

- Suitable for applications requiring moderate vacuum levels, such as HVAC systems, refrigeration, automotive brake systems, or laboratory setups.

- The range is broad enough for many industrial and mechanical uses without needing multiple gauges.

3. **1/4 NPT Threading**

- Standardized threading makes it easy to install on existing systems without requiring custom adapters.

- Compatible with common vacuum fittings in workshops and factories.

4. **Analog Readout**

- Provides a clear, direct visual indication of vacuum levels, which can be easier to interpret than digital gauges for quick checks.

- No reliance on power or electronics, making it reliable in environments with electrical interference.

5. **Durable Construction**

- McMaster-Carr products are generally built for industrial use, offering robustness against vibrations and temperature fluctuations (though specific tolerances should be checked for extreme conditions).

- The gauge housing is likely metal, providing better protection than plastic alternatives.

6. **Affordable**

- Priced competitively for an industrial-grade vacuum gauge, offering good value for basic to moderate applications.

- Avoids the higher costs of specialized or high-precision gauges.

7. **Easy to Read**

- Large dial and clear markings simplify operation, reducing the likelihood of misreading values.

---

### **Cons**

1. **Limited Precision**

- Analog gauges lack the precision of digital counterparts, which may be critical in applications requiring exact measurements (e.g., high-vacuum systems or scientific research).

- Potential for parallax error when reading the needle position.

2. **No Digital Output**

- Cannot be integrated into automated systems or data loggers without additional converters or interfaces.

- Manual recording of readings is required for documentation.

3. **Glycerin Sensitivity to Temperature**

- Glycerin can thicken or thin with temperature changes, potentially affecting accuracy in extreme environments (e.g., refrigeration units or high-heat applications).

- May require recalibration if used in fluctuating conditions.

4. **No Backing Outlet**

- Unlike some gauges with a bleed valve, this model does not allow for easy venting of the gauge without disconnecting it from the system. This can complicate maintenance or calibration.

5. **Potential for Condensation**

- While glycerin reduces moisture damage, condensation inside the gauge (from rapid temperature changes) could still affect readability or internal components over time.

6. **Single-Use Threading**

- The 1/4 NPT thread is standard but may not fit all systems without adapters, especially in older or non-standard setups.

- Over-tightening during installation could damage the thread or the gauge s seal.

7. **No Built-in Protection for Overpressure**

- Unlike some industrial gauges, this model may not have a burst disk or pressure relief mechanism, risking damage if exposed to positive pressure (e.g., reverse flow).

8. **Limited Brand Support**

- McMaster-Carr is a distributor, not a manufacturer, so warranty or replacement parts may depend on the original equipment manufacturer (OEM) or supplier policies.

---

### **Conclusion**

The **McMaster-Carr 25-500-30 VAC Glycerin-Filled Vacuum Gauge (B589)** is a practical choice for **general-purpose vacuum monitoring** in applications where durability, simplicity, and moderate accuracy are prioritized over high precision or digital integration. Its glycerin filling makes it more reliable in dirty or humid environments than standard gauges, and its wide range (25 500 VAC) covers many industrial and mechanical needs. However, it is not ideal for **high-precision, automated, or extreme-environment applications** where digital gauges or specialized models would be preferable.

---

### **Recommendation**

- You need a **durable, analog vacuum gauge** for **HVAC, automotive brake systems, refrigeration, or basic laboratory use**.

- Your system operates within the **25 500 VAC range** and does not require extreme precision.

- You prefer a **low-maintenance, no-power-required** solution with a **standard 1/4 NPT thread**.

- Cost is a factor, and you can tolerate the limitations of an analog readout.

- You require **high-precision measurements** (e.g., scientific research, semiconductor manufacturing).

- Your application involves **extreme temperatures, corrosive environments, or frequent pressure reversals**.

- You need **digital output, data logging, or automation compatibility**.

- The system already uses **non-standard fittings** that won t accommodate the 1/4 NPT thread.

- For **higher precision**: Digital vacuum gauges (e.g., Omega or Ashcroft models).

- For **extreme environments**: Stainless steel or oil-filled gauges with temperature compensation.

- For **automated systems**: Gauges with **RS-232/485 output** or **HART protocol support**.

- For **low-cost, disposable use**: Cheaper mercury-free gauges (though glycerin-filled is already an upgrade).

If your needs align with the gauge s strengths, it is a **solid, cost-effective purchase** for general vacuum monitoring. Otherwise, investing in a more specialized gauge may yield better long-term results.

Details:

part #: 2550030vac prices

• $30.00-$70.00

specifications pressureswitchiz:

• brand: Noshok
• mpn: 25-500-30-vac-mcmaster
• part type: Vacuum Gauge
• connection diameter: 1/4 In
• country of origin: Poland

offer pressureswitchiz:

• quantity: 1
• availability: In Stock
• options: Ship-to-home
• sold: 0
• started: June 4, 2026

shipping pressureswitchiz:

• service: Standard
• cost: $15.00
• transit: 4-7 Days
• class: Standard
• type: Fixed

general pressureswitchiz:

• condition: New
• Business Industrial > Hydraulics, Pneumatics, Pumps Plumbing > Air Pressure Gauges

seller pressureswitchiz:

• # reviews: 8040
• rating: 99.9%
• city: Modesto, California

payments pressureswitchiz:

• other
• credit card: Mastercard
• wallet: Paypal

returns pressureswitchiz:

• policy: Returns Accepted
• time: 14 Days
• method: Money back
• paid by: Buyer

Noshok 25-500-30-VAC Is Similar To:

• 0-2000 Gauge Filled 4 Noshok Psi Brass Liquid Diameter (26.7% similar) 375 inches nominal case material metal and plastic case surface treatment finish, black, crackle end item model e 3a graduation UNIT1000. 625 inches nominal mounting hole DIAMETER0. Pounds per square inch connection type internal mounting method flush panel actuating element material any acceptable...(April 10th, 2015)
• 013770898 Noshok Pressure Gauge Used (29.6% similar) If another carrier such as ups or FedEx is required to ship due the size, then shipping costs may change...(November 27th, 2017)
• 1000-2000-2-1 Noshok Gauge (22.9% similar) Used for one job testing, 1/4 bottom psi digital gauge...(February 10th, 2018)
• 1105174255 Noshok Liquid Filled Inhg (29.6% similar) ING 316SS tube socket. Noshok liquid filled gauge...(March 31st, 2018)
• 15-110-60-psi-kpa Noshok Lot Of Pressure Gauge (30.4% similar) 00LOT of 2000 Tao-saw technology test TV0119A ICC, CO, dam, AMD, 50 ohms emir fil 1,999. Here to via message related items barista ARP-1608AP LCD touch screen T83908 1,999. 00LOT of 500 250LDB, 022806, MSD28774, 21AA13C PCB boards T75498 1,000. 00PRECISION products E99-001, 3 Nan table surgical ...(September 6th, 2018)
• 20-110-3v Noshok Pressure Gauge 1-4 (29.8% similar) New condition Noshok pressure gauge 3v 1/4 npt 2 abs panel mount clamp free domestic shipping in: 1B98990...(September 1st, 2017)
• 20-120-100-psi-kpa Noshok Series Steel Dual Scale Dial Indicating Pressure Gauge Psi (30.7% similar) Vb industrial supply offers a huge selection of tools for every trade including new and used electrical, mechanical, machinist tooling, hydraulic pneumatic components supplies. Please with any questions or concerns. Items are not returnable for condition issues commented on or shown in the pictures...(March 9th, 2018)
• 20-120-160 Noshok Panel Mount Air Pressure Gauge Npt (33.6% similar) ...(January 19th, 2019)
• 20.120.14kg-cm2 Noshok 2 Pressure Gauge (30.5% similar) The shipper we utilize is of our choice unless arranged in advance bid or purchase. By placing an order with advanced fluid controls, you agree to accept any and all charges in addition regular shipping costs...(May 4th, 2017)
• 20.120.200 Noshok 2 Standard Pressure Gauge (34.4% similar) By placing an order with advanced fluid controls, you agree to accept any and all charges in addition regular shipping costs. 5 full scale accuracy, w panel mount. Black painted steel with chrome plated triangular bezels and u-clamps. The shipper we utilize is of our choice unless arranged in ...(February 23rd, 2017)
• Noshok Psi 25-200-100inh20 Gauge 0-100 Box (39.7% similar) ...(May 7th, 2015)