ASHCROFT 35-1133-SL-25S-250MW Differential Water Pressure Gauge

( Brand: Ashcroft ), ( Manufacturer Part Number: 35-1133-SL-25S-250MW ), ( Part Type: Pressure Gauge )

Review ASHCROFT New Nib Differential Pressure Gauge

The **Ashcroft 35-1133-SL-25S-250MW Differential Pressure Gauge** is a precision-engineered instrument designed to deliver reliable and accurate measurements of pressure differentials in industrial, HVAC, and process control applications. Part of Ashcroft s renowned **35-1133** series, this gauge combines robust construction with advanced engineering to ensure long-term performance in demanding environments. Built with a **25-inch (635 mm) dial face**, it provides a clear, easy-to-read display of pressure differentials ranging from **0 to 250 milliwatts of water (mW)** or equivalently, **0 to 250 Pascals (Pa)** making it ideal for applications requiring fine-tuned monitoring of airflow, filtration efficiency, or system balance in HVAC systems, air handling units, or industrial processes. The gauge features a **sliding magnet (SL) mechanism**, which enhances accuracy by reducing friction and wear over time, ensuring consistent readings even with frequent fluctuations in pressure differentials. Its **25S** designation indicates a **25-inch (635 mm) dial**, while the **250MW** specification confirms its optimized range for low-pressure differential measurements, such as those found in air filters, duct systems, or pressure drop monitoring across membranes and valves.

Constructed from high-quality materials, the Ashcroft 35-1133-SL-25S-250MW is built to withstand harsh conditions, with a **cast aluminum housing** that provides durability and resistance to corrosion. The gauge s **hermetically sealed** design ensures protection against dust, moisture, and contaminants, making it suitable for both indoor and outdoor installations where environmental factors could otherwise compromise performance. The **black-and-white dial** features bold, high-contrast markings and a **needle with a red tip** for quick visual identification of critical pressure points, improving operator efficiency in monitoring and maintenance tasks. Additionally, the gauge incorporates Ashcroft s **patented sliding magnet technology**, which minimizes hysteresis and backlash, delivering repeatable and precise readings even under dynamic pressure conditions. This makes it particularly well-suited for applications where accuracy is paramount, such as in **cleanroom environments, laboratory settings, or precision filtration systems**.

Beyond its technical specifications, the Ashcroft 35-1133-SL-25S-250MW is engineered with practicality in mind, offering **easy installation and calibration** through its **NPT (National Pipe Thread) connections**, which ensure a secure and leak-proof fit. The gauge s **universal mounting bracket** allows for flexible installation on walls, panels, or equipment surfaces, adapting to various industrial layouts. Its **low-maintenance design** reduces downtime, as the sliding magnet mechanism and sealed construction minimize the need for frequent adjustments or recalibration. Whether used in **HVAC systems to monitor air filter performance, in industrial processes to regulate flow differentials, or in research settings to measure subtle pressure variations**, this gauge provides a dependable solution for applications where precision and reliability are non-negotiable. With Ashcroft s reputation for quality and innovation, the 35-1133-SL-25S-250MW stands as a trusted tool for professionals who demand accuracy, durability, and ease of use in their pressure measurement needs.

### **Pros and Cons of buying a Ashcroft 35-1133-SL-25S-250MW Differential Pressure Gauge**

1. **High Accuracy and Reliability** Ashcroft is a well-known brand in industrial instrumentation, offering precision-engineered gauges with minimal drift over time. This model is designed for critical applications where accurate differential pressure readings are essential.

2. **Wide Range and Versatility** The gauge measures differential pressure from **0 to 250 MWC (millimeters of water column)**, making it suitable for low-pressure applications such as HVAC systems, filtration, and air handling units. The **25S** variant suggests it may have a **2.5-inch dial**, which provides a clear, easy-to-read display.

3. **Durable Construction** Ashcroft gauges are built to withstand harsh environments, including temperature fluctuations and vibration. The **SL** designation likely indicates a **sanitary or hygienic design**, making it suitable for food, pharmaceutical, and water treatment industries where cleanliness is critical.

4. **Easy Installation and Maintenance** The gauge is designed for straightforward mounting (likely via NPT or BSP threads) and features a **sealed back**, reducing the risk of contamination. The **250MW range** is low enough that it may not require frequent recalibration, reducing downtime.

5. **Compatibility with Various Fluids** The gauge can handle **air, water, steam, and other non-corrosive fluids**, depending on the material of the diaphragm or sealing elements. If properly specified, it can be used in applications like **ventilation systems, dust collection, and process control**.

6. **Long Lifespan** Ashcroft instruments are known for durability, often lasting **10 years** with proper maintenance, making them a cost-effective long-term solution.

7. **Brand Support and Availability** Ashcroft is a trusted manufacturer with extensive distribution networks, meaning parts and service are widely available. This reduces the risk of obsolescence compared to lesser-known brands.

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1. **Limited High-Pressure Capability** The **250MW (250 mmWC) range** is very low, meaning this gauge is **not suitable for high-pressure applications** (e.g., hydraulic systems, compressed gas lines, or industrial steam). If your application requires higher differentials, this model is not appropriate.

2. **Potential for Condensation Issues** In environments with **temperature swings or high humidity**, condensation inside the gauge housing could affect accuracy or cause damage over time. Proper drainage or a **drain port** may be needed.

3. **Cost Compared to Basic Gauges** While Ashcroft is a premium brand, this gauge may be **more expensive** than generic or lower-end differential pressure gauges from unknown manufacturers. If budget is a constraint, alternatives may exist.

4. **Specialized Applications Only** The **SL (sanitary/low-pressure) variant** is optimized for **clean, non-abrasive fluids**. If your application involves **corrosive, viscous, or highly abrasive media**, additional seals or materials may be required, increasing cost.

5. **Calibration Requirements** Like all precision instruments, this gauge may need **periodic calibration** to maintain accuracy, which could add maintenance overhead.

6. **Limited Digital Output** This is an **analog gauge** (mechanical dial), meaning it does not provide **electronic signals or digital readings**. If integration with a control system is needed, an **electronic differential pressure transmitter** may be a better choice.

7. **Potential for Glass Breakage** Some Ashcroft gauges use **glass-bourdon tubes**, which can shatter under extreme pressure spikes or mechanical stress. While rare, this could lead to **liquid leaks or safety hazards** if not properly protected.

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### **Conclusion**

The **Ashcroft 35-1133-SL-25S-250MW differential pressure gauge** is an **excellent choice** for **low-pressure, sanitary, or clean-environment applications** where **accuracy, durability, and brand reliability** are priorities. It is well-suited for **HVAC systems, filtration, food processing, and water treatment**, but **not for high-pressure or harsh industrial settings**.

If your application involves **high differential pressures, corrosive fluids, or requires digital integration**, this gauge may not be the best fit, and alternatives (such as a **transmitter or a higher-range mechanical gauge**) should be considered.

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### **Recommendation**

You need a **low-pressure (0-250 mmWC) differential measurement** in a **clean, sanitary environment**.

**Reliability and brand reputation** (Ashcroft) are important for your application.

You require a **mechanical, analog display** and do not need electronic signaling.

Your system involves **air, water, or mild process fluids** without abrasive particles.

Your application requires **higher pressure ranges** (e.g., above 1000 mmWC).

You need **digital output or integration with PLCs/SCADA systems** (opt for a **transmitter**).

The environment is **extremely harsh** (high vibration, extreme temperatures, or corrosive media).

Budget constraints make a **lower-cost generic gauge** a viable option.

For **low-pressure, precision-critical, sanitary applications**, this Ashcroft gauge is a **strong, long-term investment**. However, if your needs differ significantly, a more specialized or higher-range instrument may be necessary. Always verify **fluid compatibility, installation conditions, and calibration requirements** before purchase.

Details:

New NIB Ashcroft 35-1133-SL-25S-250MW Differential Pressure Gauge, Max: 35.0 bar / 525 psi Max: 80' C 176' F Whetted Parts: SS316 Porting: 1/4 NPT F Dial: 80mm 3.5 Seals: Buns-N, NOL B-2-1 Buns-N.

part #: 351133sl25s250mw prices

• $89.95-$499.97

specifications pressureswitchiz:

• brand: Ashcroft
• mpn: 35-1133-sl-25s-250mw
• part type: Pressure Gauge

general pressureswitchiz:

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

seller pressureswitchiz:

• rating: 99.8%
• # reviews: 14142
• city: Mound, Minnesota

offer pressureswitchiz:

• sold: 0
• started: February 25, 2026
• availability: In Stock
• quantity: 2
• options: Ship-to-home

returns pressureswitchiz:

• paid by: Seller
• policy: Returns Accepted
• time: 60 Days
• method: Money back

shipping pressureswitchiz:

• transit: 2-5 Days
• cost: $0.00
• service: USPS Priority Mail, UPS 2nd Day Air, UPS Next Day Air
• carrier: USPS, UPS
• class: Expedited, One-day
• type: Calculated

payments pressureswitchiz:

• other
• wallet: Google-pay
• credit card: Visa

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