Product Description

The FOXBORO 13A-MS2-R is a pneumatic differential pressure (d/p Cell) transmitter from the highly regarded Foxboro 13A series. These transmitters, now part of Schneider Electric, are renowned for their robust and reliable performance in the process industry, particularly in applications where pneumatic signals are preferred or required. This specific model measures differential pressure and then converts it into a standard pneumatic output signal, typically 3-15 psi (pounds per square inch), for transmission to receiving instruments or control systems located remotely.

The “MS2” in the model code indicates specific characteristics of the transmitter’s capsule and range, with “M” referring to a medium-range capsule (typically 0-250 inH2O). The significant addition here is the “-R” suffix. In the context of Foxboro 13A transmitters, the “-R” suffix typically denotes the inclusion of an optional Zero Suppression Kit. This kit allows for extended adjustment of the measured pressure range within the full limits of the capsule, enabling “suppressed-zero” ranges. This is particularly useful for liquid level applications where the measured level never goes down to zero, or for differential pressure applications where the minimum pressure is above zero, allowing for higher resolution and accuracy over a specific, elevated span.

The FOXBORO 13A-MS2-R is commonly used in flow measurement (often with orifice plates), liquid level (especially suppressed-zero level in tanks), and other differential pressure applications where pneumatic instrumentation is chosen due to safety requirements in hazardous areas or for integration into existing legacy pneumatic control loops. It offers excellent span adjustability and zero suppression/elevation capabilities, providing significant flexibility for diverse industrial processes. The transmitter features a durable construction, typically with 316 Stainless Steel wetted parts, to ensure longevity in various process environments.

Product Parameters

The FOXBORO 13A-MS2-R possesses the following key technical specifications:

Advantages and Features

The FOXBORO 13A-MS2-R offers several advantages and features, building on the core strengths of the 13A series with enhanced range flexibility:

• Integrated Zero Suppression/Elevation (-R suffix): This is the key advantage. The included kit allows for precise adjustment of the measurement span to start at a non-zero value (suppressed zero) or end at a non-zero value (elevated zero). This optimizes accuracy for applications where the process variable operates within a narrow band that is not zero-based.
• Proven Reliability: Foxboro d/p Cell transmitters are a long-standing industry standard, known for their durable and accurate performance in harsh industrial settings, ensuring consistent and dependable operation.
• Pneumatic Output: Generates a standard 3-15 psi pneumatic signal, which is intrinsically safe for hazardous or explosive environments, making it ideal where electrical signals are undesirable or restricted. It seamlessly integrates into existing pneumatic control infrastructure.
• Versatile Measurement: Perfectly suited for common process measurements such as liquid level (especially where zero suppression is needed for tank levels), flow (using primary flow elements like orifice plates), and general differential pressure monitoring.
• Wide Span Adjustability: Beyond the “-R” kit, the transmitter itself offers broad span adjustability within the ‘M’ capsule’s limits to match specific process requirements.
• Robust Construction: Built with durable materials like 316 Stainless Steel for wetted parts, ensuring chemical compatibility with various process fluids and a long operational lifespan.
• Easy Maintenance: The modular design, including a field-replaceable capsule and easily accessible topworks, simplifies maintenance and reduces overall service costs. Shared parts with other Foxboro pneumatic transmitters can minimize spare parts inventory.
• High Static Pressure Rating: Designed to withstand high line pressures (up to 2000 psi), making it suitable for high-pressure process applications.
• Environmental Durability: The housing provides strong environmental protection (IP53/NEMA 3), making it resistant to dust and various weather conditions.

Application Areas and Application Cases

The FOXBORO 13A-MS2-R is widely applied in industries that utilize pneumatic control systems for differential pressure measurement, particularly in processes involving liquids, gases, and steam within medium pressure ranges, with a specific advantage for non-zero-based measurements:

• Liquid Level Measurement (Suppressed Zero): Ideal for measuring liquid level in storage tanks or vessels where the low-pressure tap is significantly above the minimum liquid level (e.g., bottom of tank) or where the vessel is always partially filled. The “-R” kit allows the 3-15 psi output to correspond precisely to the actual operating liquid level range.
• Flow Measurement: Monitoring flow rates in chemical and petrochemical lines, refining processes, and power generation where pneumatic signals are used.
• Differential Pressure across Equipment: Measuring pressure drop across filters, heat exchangers, or columns to monitor fouling or process conditions, especially where the normal operating differential pressure is not near zero.
• Chemical and Petrochemical Plants: Level measurement in distillation columns, reactors, or storage tanks where the initial level is above the sensing element, and flow applications in hazardous areas.
• Water Treatment Facilities: Monitoring differential pressure across various filtration stages, where a baseline differential pressure is always present.

Application Case: In a chemical plant, the level of a solvent in a large storage tank needed to be continuously monitored. The tank’s design dictated that the lowest tapping point for the differential pressure transmitter was 2 meters above the actual tank bottom, and the tank was never allowed to empty below this point. To get an accurate reading that corresponded to the actual liquid level above the lowest possible point, a FOXBORO 13A-MS2-R differential pressure transmitter was installed. The “M” capsule provided the appropriate measurement range, and the “-R” (Zero Suppression Kit) was crucial. It allowed the 3 psi output to be configured to correspond to the 2-meter baseline, and the 15 psi output to correspond to the maximum desired liquid level. This ensured that the 3-15 psi pneumatic signal accurately represented the actual operating range of the liquid level, providing precise control and inventory management without needing complex calculations or external signal conditioning.

Competitive Comparison

The FOXBORO 13A-MS2-R operates within the niche market of pneumatic differential pressure transmitters, with the added capability of native zero suppression. While the broader industrial instrumentation market has largely transitioned to electronic transmitters, pneumatic devices like the 13A series remain vital for legacy systems, certain intrinsically safe applications, or where electrical infrastructure is limited.

Historically, competitors in the pneumatic differential pressure transmitter space with similar capabilities would have included specific models from:

• Rosemount (now Emerson): Offered pneumatic versions of their classic 1151 series, some of which had adjustable zero/span features.
• Honeywell: Had its own line of pneumatic transmitters.
• Taylor (now ABB): Produced various pneumatic instruments that competed with Foxboro’s offerings.

The FOXBORO 13A-MS2-R differentiates itself through:

• Integrated Zero Suppression/Elevation: The “-R” suffix indicates that this functionality is built-in and factory-configured or field-installable as a standard option, making it very convenient for applications requiring non-zero-based ranges.
• Established Reliability: The Foxboro d/p Cell is widely recognized for its robust and stable performance over decades, making it a preferred choice for replacement or expansion in existing pneumatic systems.
• Ease of Service: Its modular design, including readily interchangeable parts, simplifies maintenance and calibration, often reducing downtime and overall cost of ownership for users already familiar with the Foxboro pneumatic line.
• Specific Range (Medium): The “M” capsule is optimized for medium differential pressure ranges, providing tailored accuracy and performance for those specific applications.
• High Static Pressure Capability: The ‘M’ capsule maintains a high static pressure rating, allowing its use in high-pressure process lines.

While modern electronic transmitters offer superior accuracy, advanced diagnostics, and seamless digital integration (often with software-configurable range/zero suppression), the FOXBORO 13A-MS2-R continues to be a crucial component for plants maintaining pneumatic infrastructure due to its unparalleled reliability, simplicity, safety benefits, and specific utility for suppressed/elevated range applications.

Selection Advice

When selecting the FOXBORO 13A-MS2-R, consider the following:

• Pneumatic System Integration: This transmitter provides a pneumatic output signal. Ensure your existing or planned control system (DCS, pneumatic controller, indicator) is compatible with a 3-15 psi input signal.
• Need for Zero Suppression/Elevation: The “-R” suffix is significant. Choose this model if your application requires the measured span to be adjusted to a non-zero starting or ending point (e.g., for liquid level measurement where the minimum level is not zero). If a simple 0-250 inH2O range is sufficient, a standard 13A-MS2 might suffice.
• Process Medium and Conditions: Verify that the wetted parts materials (e.g., 316 SS for body and capsule) are chemically compatible with your process fluid and can withstand the process temperature and pressure.
• Differential Pressure Range: Confirm that the 0-250 inH2O range of the ‘M’ capsule covers your application’s expected differential pressure variation, especially considering the effects of zero suppression.
• Static Pressure: Ensure the maximum static pressure of your process line does not exceed the transmitter’s static pressure limit (2000 psi).
• Supply Air Quality: Reliable operation is dependent on a consistent supply of clean, dry, instrument-quality air at the specified pressure (typically 20-30 psi). Proper filtration and regulation are essential.
• Installation Environment: Consider the mounting options (pipe mounting bracket included) and ensure the environmental protection (IP53/NEMA 3) is sufficient for your ambient conditions.
• Replacement or New Installation: The 13A-MS2-R is primarily chosen for replacement in existing pneumatic systems. For new installations, carefully evaluate whether the advantages of modern electronic transmitters (e.g., higher accuracy, digital communication, lower energy/air consumption) are more beneficial for your overall system design.

Precautions

When installing and operating the FOXBORO 13A-MS2-R, observe the following critical precautions:

• Pressure Isolation and Venting: Always ensure process connections are isolated and all residual process pressure is safely vented before attempting any maintenance, calibration, or removal of the transmitter. Follow strict lockout/tagout procedures.
• Supply Air Quality: Contaminated air (moisture, oil, particulates) is a common cause of pneumatic instrument failure. Ensure a continuous supply of clean, dry, instrument-quality air at the correct pressure. Install appropriate air filters and regulators upstream.
• Material Compatibility: Double-check that the wetted parts materials (diaphragm, body, process connections) are fully compatible with your process fluid to prevent corrosion, leakage, and potential safety hazards.
• Over-pressure Protection: Do not expose the capsule to pressures exceeding its specified static or differential limits. Implement appropriate over-pressure protection mechanisms if process pressure surges are anticipated.
• Mounting Orientation: While the 13A series can be mounted up to 90∘ from vertical, significant zero shift can occur. Ensure the transmitter is mounted in the specified orientation and properly zero-adjusted after installation, especially when utilizing the zero suppression feature.
• Vibration Control: Excessive mechanical vibration can negatively impact measurement accuracy and the lifespan of pneumatic components. Mount the transmitter securely to minimize vibration transmission.
• Temperature Extremes: Operate the transmitter within its specified ambient and process temperature limits. Exceeding these limits can degrade performance or damage internal components.
• Qualified Personnel: Installation, calibration, troubleshooting, and maintenance should only be performed by qualified and experienced personnel familiar with pneumatic instrumentation, pressure measurement principles, and relevant safety regulations. Precise adjustment of the zero suppression/elevation using the “-R” kit requires careful calibration procedures.