Rosemount 3051SFA Annubar Flow Meter

Rosemount 3051SFA Annubar flow meter: averaging pitot tube with a 3051S transmitter

The Rosemount 3051SFA is an integrated differential pressure flow meter that pairs an Annubar averaging pitot tube with a Rosemount 3051S transmitter. The T-shaped sensor creates less blockage in the pipe than an orifice, so permanent pressure loss is low, and the all-welded SuperModule design is aimed at harsh sites. The manufacturer positions the 3051SFA for large line sizes, where cost, size and weight of the flow meter matter, and sizes are offered from 2 in. (50 mm) to 96 in. (2400 mm).

Seven Star LLC supplies Rosemount flow instrumentation in Oman and the GCC as an independent supplier in Muscat. The model code of the 3051SFA is long, so this page explains how it is built and what to settle before an RFQ.

Decoding the 3051SFA model code

The manufacturer shows a typical code, 3051SFA D L 060 D C H P S 2 T1 0 0 0 3 2A A 1A 3, which can be read against the ordering tables as below.

The listing of the example is the manufacturer's own and is a guide to the structure; the exact digits of any order must come from the configurator. If you have a sizing sheet, we can match a code to it.

3051SFA technical specifications

How the 3051SFA measures flow

The Annubar sensor spans the pipe diameter. Several sensing ports on the upstream face average the velocity profile into a high-pressure chamber, while the downstream side gives a low-pressure signal. The 3051S module measures the difference, and the built-in flow computation turns it into flow rate. With measurement types 1 to 4, the flow meter calculates compensated mass or volumetric flow from differential pressure plus the static pressure and temperature inputs that are selected.

Measurement type 1 gives fully compensated mass and energy flow using differential pressure, static pressure and temperature. Types 5 to 7 output process variables only, and type D outputs differential pressure alone. A temperature sensor is required for types 1, 3, 5 and 7, which is why the integral RTD in the sensor, or a remote thermowell, is part of the ordering decision.

3051SFA mounting styles: Pak-Lok, Flange-Lok and Flo-Tap

Flo-Tap models need a packing gland and an isolation valve; the valve is selectable as carbon or stainless gate or ball valve, or it can be customer supplied. Flanged models require an opposite-side support, and Pak-Lok and Flange-Lok models do not use one. Piping orientation must be stated as horizontal, vertical down or vertical up.

The same data sheet covers the 3051SFC compact orifice flow meter, the 3051SFP integral orifice flow meter and the primary elements used with them. The stand-alone Annubar primary elements are the Rosemount 485 and the bi-directional 585. The 3051SFC and 3051SFP serve smaller lines, so the 3051SFA is the member of the family for large pipe. The 3051CFA and 2051CFA belong to the separate 3051CF and 2051CF families built on the 3051C and 2051C transmitters.

Selecting a 3051SFA: ordering and sizing checklist

• Fluid, composition, line pressure and temperature, and flow range from minimum to maximum.
• Pipe size, inner diameter, wall thickness and material for the custom-built sensor length.
• Orientation and straight-run availability, and whether insertion under pressure (Flo-Tap) is needed.
• Mounting connection: threaded, ASME flange class or EN flange, with RF or RTJ face.
• Sensor material for the medium, and whether a flow reading with compensation is required (measurement type).
• Temperature sensing: integral RTD, remote thermowell, or none.
• Transmitter platform: direct 3-valve or 5-valve manifold, or remote mount, plus output and housing.

Installing and maintaining the 3051SFA

Follow the sizing report for straight-run needs and the drawing for orientation, because the sensor is built to the pipe inner diameter you supplied. Direct-mount manifolds on hot lines must respect the 500 °F limit; above it use the high-temperature 5-valve manifold or a remote mount. Steam service with Flange-Lok or Pak-Lok connections is limited to 600 °F (316 °C).

Routine care is mainly checking the manifold valves and verifying the transmitter zero. The advanced diagnostics of the 3051S are described by the manufacturer as detecting abnormal process conditions and electrical loop issues, and the flow meter can be ordered with hydrostatic testing, PMI and material certificates when project documentation demands it.

3051SFA applications in Oman and the GCC

Large-bore services are the natural home of the Annubar: cooling water, seawater intake and brine lines in desalination, boiler feedwater and steam headers in power plants, flare and fuel gas headers in oil and gas, and process air or nitrogen in petrochemical complexes. Low permanent pressure loss matters on pumped lines where energy cost accumulates over years.

The all-welded 3051S module and 316 stainless sensor suit hot, humid coastal locations. For fouling services with deposits, scale or solids, confirm with the sizing report that an averaging pitot tube is suitable.

Information to send with a 3051SFA RFQ

• Sizing data sheet or line list entry: fluid, pressures, temperatures, flows, pipe ID and schedule.
• Measurement type wanted and whether energy flow is needed.
• Annubar type, mounting, sensor material and isolation valve.
• Transmitter output, housing, display, and hazardous-area approval.
• Quantity, delivery site and project documentation list.

Documents and quotation

The manufacturer product data sheet for the Rosemount DP flow meters and primary elements is attached on this page. It includes the ordering tables, performance, temperature limits and physical specifications for the 3051SFA.

To request a quotation, send the full model code or your sizing data. Seven Star LLC will check the configuration and respond with availability for Oman and the GCC.