Flow computer handles critical oil mass and volume calculations

New meter prover interface feature from ProSoft Technology performs sophisticated functions on Rockwell’s ControlLogix platform.

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ProSoft Technology has announced version 2.07 of its Liquid and Gas Flow Computer for the Rockwell Automation ControlLogix platform (MVI56-AFC). In oil applications, crude is extracted and transported through pipelines that often run hundreds of miles through varying climates, temperatures, and altitudes. As these elements vary, so do the properties of the petroleum, necessitating flow computers to validate the precise quantity of product at designated points along the pipeline. Precise flow calculations require accurate data from properly calibrated flow meters. Meter provers help validate proper flow meter operation.

The ProSoft Technology flow computer calculates a meter factor based on constants and variables affecting flow rates, accumulated volumes, and accumulated mass of the liquid petroleum product flowing through a prover with known volume. With the new meter-proving feature, the module is now able to communicate meter-prover test results directly to the control processor and SCADA control system. Operation of the prover-interface feature can be performed manually, completely automated, scheduled, triggered by events, or operator intervention.

The prover interface feature supports these prover types:

• Unidirectional pipe prover;
• Bidirectional pipe prover;
• Compact prover; and
• Master meter prover.

The module resides directly in the ControlLogix chassis, acting as an add-on co-processor, dedicated to calculating flow measurements without burdening the PLC with complicated flow algorithms. Additional features include:

• Multiple, independently-configuratble meter streams: The module supports up to 16 meter runs with four streams per meter and allows the PLC/PAC to switch the active stream via program logic. Each of the channels are individually configurable to calculate hydrocarbon gas or liquid flows.

• High precision analysis for multiple streams: Fractional components of hydrocarbon gases may be entered as floating-point values with precision of seven or more significant digits.

• Completely automated control: The module is programmed, managed, and monitored by the PLC or SCADA system.

• Complies with AGA 3, 7, 8, and MPMS Chapters 11 and 12.2 measurement standards.

• Event log lockout security: Prevents overwriting past events which have not yet been downloaded and archived in some off-module system.

• Modbus dictionary: This index allows users to locate the Modbus address of needed data.

www.prosoft-technology.com

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Edited by Peter Welander, pwelander(at)cfemedia.com