Rosemount 2051 Pressure Transmitters

Technical Dossier

Product Details And Specifications

Rosemount 2051 Series: Comprehensive Pressure Transmitter Range and Technical Overview

The Rosemount 2051 is one of the most widely deployed pressure transmitter platforms in global heavy industry. Manufactured by Emerson (formerly Fisher-Rosemount), the 2051 series is installed across petrochemical complexes, nuclear power stations, offshore oil platforms, LNG terminals, and refinery process units worldwide. Its installed base spans decades of continuous operation, making it a cornerstone instrument in distributed control system (DCS) architectures built on platforms such as Emerson DeltaV, Honeywell Experion, ABB 800xA, and Yokogawa CENTUM.

The 2051 series covers differential pressure (DP), gauge pressure (GP), and absolute pressure (AP) measurement with output options including 4–20 mA HART, FOUNDATION Fieldbus, and WirelessHART. Its modular construction — separating the sensor module from the electronics housing — allows field replacement of individual assemblies without full instrument removal, a critical advantage in continuous-process environments where downtime carries significant financial penalties.

The Evolution of 2051 Architecture

The Rosemount 2051 platform was introduced in the early 1990s as a successor to the Rosemount 1151 series, which had defined analog pressure measurement in process industries since the 1970s. The transition from 1151 to 2051 represented a shift from purely analog signal conditioning to smart transmitter architecture with digital communication capability via the HART protocol.

Generation 1 (1990s): Initial 2051 models featured basic HART rev 5 communication, ±0.1% accuracy, and a 10:1 rangeability. These units are now fully obsolete but remain in service at facilities that have deferred instrumentation upgrades.

Generation 2 (2000s): Introduction of the Coplanar flange design (2051C suffix), enabling direct mounting to 3-valve and 5-valve manifolds. This generation also introduced the enhanced sensor module with improved stability specifications and expanded temperature compensation ranges. FOUNDATION Fieldbus variants (FF suffix) became available, enabling integration into fieldbus segment architectures.

Generation 3 (2010s–present): The current production 2051 platform incorporates advanced diagnostics (statistical process monitoring, plugged impulse line detection), WirelessHART capability (2051 Wireless), and expanded material options for aggressive process fluids. The electronics module was redesigned for improved EMI immunity and extended operating temperature range. Compatibility with legacy sensor modules was maintained, allowing electronics upgrades without sensor replacement.

Facilities operating Generation 1 and early Generation 2 units face increasing challenges in sourcing replacement electronics modules and sensor assemblies. DriveKNMS maintains inventory of both current-production and legacy 2051 components to support lifecycle extension programs.

Rosemount 2051 Full Catalog & Functionalities (SKU List)

The following SKUs represent the core of the Rosemount 2051 product matrix. Models are classified by measurement type and output protocol.

Differential Pressure (DP) — Coplanar Flange Mount:

2051CD0A02A1AS3I1M5: DP transmitter, range 0–0.25 inH₂O, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CD1A02A1AS3I1M5: DP transmitter, range 0–2.5 inH₂O, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CD2A02A1AS3I1M5: DP transmitter, range 0–25 inH₂O, 4–20 mA HART, SST wetted parts, coplanar flange — current listing SKU base.
2051CD3A02A1AS3I1M5: DP transmitter, range 0–250 inH₂O, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CD4A02A1AS3I1M5: DP transmitter, range 0–2500 inH₂O, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CD5A02A1AS3I1M5: DP transmitter, range 0–2500 psi, 4–20 mA HART, SST wetted parts, coplanar flange.

Gauge Pressure (GP) — Coplanar Flange Mount:

2051CG1A02A1AS3I1M5: GP transmitter, range 0–30 psi, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CG2A02A1AS3I1M5: GP transmitter, range 0–300 psi, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CG3A02A1AS3I1M5: GP transmitter, range 0–3000 psi, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CG4A02A1AS3I1M5: GP transmitter, range 0–6000 psi, 4–20 mA HART, SST wetted parts, coplanar flange.

Absolute Pressure (AP):

2051CA1A02A1AS3I1M5: AP transmitter, range 0–30 psia, 4–20 mA HART, SST wetted parts, coplanar flange.
2051CA2A02A1AS3I1M5: AP transmitter, range 0–300 psia, 4–20 mA HART, SST wetted parts, coplanar flange.

Traditional (Non-Coplanar) Mount:

2051T: In-line pressure transmitter for gauge and absolute measurement, direct process connection, compact form factor for space-constrained installations.
2051TG1A02A1AS3I1M5: In-line GP transmitter, range 0–30 psi, 4–20 mA HART.
2051TG4A02A1AS3I1M5: In-line GP transmitter, range 0–6000 psi, 4–20 mA HART, high-pressure process applications.

FOUNDATION Fieldbus & WirelessHART Variants:

2051CD2A02A1FF3I1M5: DP transmitter, range 0–25 inH₂O, FOUNDATION Fieldbus H1 output, coplanar flange.
2051CD3A02A1FF3I1M5: DP transmitter, range 0–250 inH₂O, FOUNDATION Fieldbus H1 output, coplanar flange.

Manifold Option (Current Listing Full SKU):

2051CD2A02A1AS3I1M5 405PS100N065D3H: Complete assembly — 2051CD2 DP transmitter with Rosemount 405 Annubar primary element, 100mm pipe size, 65mm insertion depth, 316 SST, HART output. Configured for flow measurement in process piping.

Sourcing Hard-to-Find & Obsolete 2051 Parts

The Rosemount 2051 series spans over 30 years of production. A significant portion of the installed base consists of units manufactured between 1995 and 2010 that are no longer in active production. Emerson has discontinued several sensor module variants, electronics assemblies, and housing configurations from this period.

DriveKNMS maintains a dedicated inventory program for legacy 2051 components, including:

• Discontinued sensor modules (Range Codes 0 and 1 in early coplanar configurations)
• Legacy electronics assemblies with HART rev 5 compatibility
• Obsolete terminal block assemblies and housing covers for first-generation units
• Hard-to-source manifold assemblies and direct-mount adapters
• Complete refurbished 2051 transmitters tested to OEM specification

For facilities operating under long-term maintenance contracts or managing aging DCS infrastructure, DriveKNMS provides bill-of-materials (BOM) cross-referencing to identify current-production equivalents or certified refurbished replacements for discontinued part numbers. Inquiries for bulk or project quantities are handled directly by our technical sales team.

Quality Control for the 2051 Range

All Rosemount 2051 units processed by DriveKNMS undergo a structured inspection and functional verification protocol prior to dispatch:

• Visual and mechanical inspection: Housing integrity, process connection thread condition, nameplate legibility, and terminal block condition are verified against OEM acceptance criteria.
• Electronics functional test: Each unit is powered and interrogated via HART communicator (375 or 475 Field Communicator) to confirm device identity, configuration parameters, and diagnostic status registers.
• Calibration verification: Sensor output is verified at zero, mid-span, and full-scale against a traceable reference standard. Units outside ±0.1% of URL are recalibrated or flagged for sensor module replacement.
• Pressure leak test: Process wetted assemblies are pressure-tested at 1.5× maximum working pressure to verify diaphragm and process connection integrity.
• Output signal verification: 4–20 mA loop output is verified across the calibrated range. For FF units, block configuration and function block execution are confirmed.
• Documentation: Each unit ships with a calibration certificate, test report, and configuration record.