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FLEXIM Americas Corporation is a wholly owned subsidiary of Flexim GmbH, established in the United States in 2005 as the North & Central American Office to manage engineering, development, production Sales & Marketing and After-sale Services to our customer in the region. Since this time FLEXIM Americas has successfully delivered over 8,000 metering solutions for the most demanding of metering conditions including to all of the majors in the Oil & Gas sector.
2 Ultrasonic Flowmeter Measuring Principle
The proposed flow meter employs the transit time difference principle for flow measurement. Ultrasonic signals are emitted by a transducer installed on one side of a pipe, reflected on the opposite side and received by a second transducer. These ultrasonic signals are emitted alternatively in the direction of flow and against it.
As the medium in which the signals propagate is flowing, the transit time of the ultrasonic signals in the flow direction is shorter than against the flow direction.
The transit time difference Δt is measured and allows to determine the average flow velocity on the propagation path of the ultrasonic signals. A flow profile correction is then performed in order to obtain the area average of the flow velocity, which is proportional to the volume flow.
Figure 1: Transit time difference correlation principle
The received ultrasonic signals will be checked for their usefulness for the measurement and the plausibility of the measured values will be evaluated. The complete measuring cycle is controlled by the integrated microprocessors. Disturbance signals will be eliminated.
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3 General Specifications• Flow Velocity: .03 - 120 ft/sec (pipe size dependent)• Stated Accuracy: 1 - 3% of reading +/- .03 ft/sec• Typical Accuracy: 0.5% - 1.5% (with dual beam – single beam accuracy might be
affected by flow profile, upstream piping conditions)• Repeatability: 0.15%
• About 100 psi with standard pipes• About 300 psi with thick wall pipes• Ambient pressure with plastic pipes
4 Standard Volume
Meters that require standard Volume correction are equipped with temperature and pressure inputs for volume compensation. Compensated volume also requires a compressibility factor. Flexim has an internal compressibility curve based on a standard natural gas composition (95%) methane, and also for the gas mediums listed in the meters menu. For a specific gas Flexim can make and install a custom compressibility curve.
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Standard Volume Calculation:
5 Mounting and typical installation
Single versus Dual channel configurations: A single channel meter incorporates one set of transducers. A Dual channel meter incorporates 2 sets and computes the average velocity: The decision to purchase a single channel or dual channel meter is one of price/performance. With adequate straight run of pipe a single beam performance will be similar to a dual beam. A dual beam will have repeatability in the order of 1.0 to 0.5% better than a single beam. With shorter straight runs a dual channel is recommended because flow profile errors will have a greater effect on the accuracy.
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Single Channel Dual Channel
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Typical Installations
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6 Laboratory Calibration Results
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“Out of Box 3rd Party testing on pipe sizes 4”, 8”, 12” & 20”, by CEESI Labs verifies meter accuracy typically 1.5%
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7 Requirements & Application Analysis
The application condition requirements for the application are:
Pipe Size: OD, WTMedium Natural Gas Minimum PressureTemp (min/max) Hazardous Area Class I Div 2 Available Straight RunPower 110AC Actual or Std Volume Inputs Outputs 4-20ma, 0-5KHz, 3 Binarys
8 Description of the proposed ultrasonic flowmeter
8.1 Features/Benefits
The proposed ultrasonic flowmeter has the following features:
“Fit for Purpose” FLEXIM Transducers – Factory “matched” and calibrated Stainless Steel Transducers (hermetically sealed) and armored stainless steel cable delivers the robustness required of a portable or permanent device. “Intelligent” design – transducer contains a microchip read by the meter that contains the calibration information. Competing devices are error prone when the transducer type is not input correctly.
Transducer Temperature Compensation – The only Clamp-on meter that employs an RTD inside the transducer block as per ASME MFC 5M. A temperature algorithm compensates for calibration shifts due to temperature changes. Without this compensation the accuracy drift due to temperature change will 1% for a 30degF change.
PermaLokTrack Mount System – For permanent installations the Stainless Steel PermaLok Track provides the highest level of transducer support and protection. Flexim has engineered a permanent solid coupling material for sonically coupling the transducer to the pipe. With the protection of the PermaLok track and the permanent coupling pads there is no need to periodically re-couple transducers.
Broadened Application Range – Flexim incorporates a dynamic power delivery scheme that delivers the power to the transducers required to get the signal through the liquid or gas stream.
Ease of Use – The meter is designed to be intuitive and is very easy to program. Installation of entire meter can be easily accomplished in less than 4 hours.
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FLEXIM “Flexibility” – All Flexim meters can be configured to “adapt” to the application conditions at hand. If the upstream straight run is less than 10 diameters , the users may employ a number of mitigating techniques:
o ‘Multi-bounce’ transducer mounting allows the meter to average out local disturbances of the flow profile over a longer axial distance on the pipe. An even number of traverses (up to 8) simply cancels all cross-flow, non-axial influences on the flow velocity measured.
o Proper location of the interrogating sonic beam (in the plane of an upstream elbow for example) assures that the instrument will ‘see’ the fast flowing core of the liquid flow stream.
o Multi-beam interrogation of the flow stream through the use of two or more transducer pairs will tend to average out locally asymmetrical distribution of the flow velocity field.
Reduced Noise Susceptibility – All Flexim flow computers are fully shielded and utilize TRIAX cabling (provides for an additional armored outer shield) to prevent/minimize the influence of external noise sources.
Signal Detection – The signal processing of the transmitted signal is NOT based upon a ZERO crossing detection which relies heavily on a “match” between the wall thickness of the pipe and a selected transducer’s operating frequency. Rather FLEXIM employs a signal correlation function in which the entire receive signal is utilized resulting in a more robust signal detection process.
Application Guarantee – All meters sold. FLEXIM goes to great lengths to qualify each and every application and as such provides an application guarantee on each meter sold. We will ensure that satisfaction with ALL metering solutions provided by FLEXIM.
Support – In addition to FLEXIM’s full-service operation center on Long Island, New York, Rep office in Bridgeport, CT and we have factory certified sales and service representatives throughout located throughout the US and Canada. Flexim provides a “free” telephone hotline for assistance “when you need it”, including after hours 7 days a week till 12AM.
Total Cost of Ownership – No need for recalibration, no wear mechanism, no pressure drop, no additional flanges, valving, by-pass, etc...
Proven Reliability – 190 year calculated MTBF
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8.2 Technical Data of Instruments Offered
8.2.1 FLUXUS ADM G704
FLUXUS ADM G704 is designed especially for Hydrocarbon measurement of GAS &Liquids. Standard compensated or Mass is available by combining the attributes of FLEXIM’s highly accurate and reliable non-intrusive ultrasonic flow measurement with optional temperature and pressure inputs.
Figure 2: ADM G704
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Technical Data ADM G704Measureable flow velocity: 0.03 to 115 ft/sec
Repeatability: 0.15 % of reading ±0.01 m/sAnticipate Accuracy:Traceable wet flow calibration at factory
1 to 1.5 % of reading ±0.01 m/s
Operating temperature: -20 to +50 °CIngress protection: IP66 / NEMA 4X
Area Certification: FMC Class I Div 2Power supply: 110/220 VAC
Outputs:
Modbus RTU (Optional)RS-4852 x 4-20 mA active 3 x Relay Frequency (Optional)Internal Datalogger
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Dimensions
Figure 3: External Dimension of G704
Figure 4: Wall and 2 “Pipe Mounting Kit for ADM7407
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8.2.2 Transducer
The proposed transducer is FM-C certified for use in Class 1 Div 2 hazardous area. The transducers together with the transmitter receive a calibration with water as medium. The proposed transducer is delivered with a calibration certificate.
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8.2.3 Transducer Mounting Fixture: PermaLok Track
The PermaLok mounting fixtures hold the transducers safely in place and ensure continuous and constant contact pressure between the transducers and the pipe surface, even if temperature variations cause the pipe diameter to change. Made of stainless steel, they are corrosion-proof and wear resistant. The transducers can be removed and remounted onto the PermaLok track without readjustment. Flexim has engineered a permanent solid coupling material for sonically coupling the transducer to the pipe. With the protection of the PermaLok track and the permanent coupling pads there is no need to periodically re-couple transducers.
9 Installation
9.1 Installation Mode
The proposed installation mode will be that of a 1 PATH (REFLECT MOUNT) SINGLE CHANNEL mounting arrangement. A general arrangement drawing can be found below:
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10 Bill of Materials
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Please issue purchase order(s)
FLEXIM AMERICAS CORPORATION250-V Executive Drive Edgewood, NY 11717Terms: NET 30FOB: FactoryFreight: Pre-Pay and AddValidity: 90 Days
11 Commissioning Services
FLEXIM service engineer can assist in the installation and start-up of the hardware being proposed. This service assumes that the flow computers and junction boxes are mounted, appropriate conduit is run to the pipes, transducer and temperature cable is pulled to the flow computer and transducers and temperature junction boxes, and A/C power is connected to the meter. FLEXIM’s service engineer will be responsible for installing flow and temperature transducers, terminating transducer and temperature cables and performing calibration and commissioning of each system.
Scope of Work:Work Performed by Other:
Mount metersRun and install power to metersRun Conduit for Power / Transducer Cables / Temperature CablesRun cables in conduit (when required)
Work Performed by Flexim:Terminate Transducer / Temperature Cables Install Transducers / Temperature sensors on Pipe – Note: This will require cutting insulation - every attempt will be made to leave the insulation intact but insulation touch up may be required (by others).
Support Requirements:On Site personnel to provide the following logistical support to Flexim personnel
Escort and access to the installations sitesLadders / External Power / Lighting / Access
12 Delivery and WarrantyThe terms of delivery shall be within 4 weeks from the date of order confirmation / technical clarification.
Flexim guarantee that the design, engineering and the instrument supplied shall be free from defects. All defective material shall be replaced free of charge within 12 months from the date of delivery of the instruments whichever comes earlier.