Description
1. Overview
The DigitalFlow XGF8681-21-OIM-34-0 is an industrial high-precision flare gas ultrasonic mass flowmeter manufactured by Baker Hughes Panametrics. Belonging to the XGF868i series, it is specially designed for flare vent systems in petrochemical, refining, oil and gas, and power plant industries. Adopting transit-time ultrasonic measurement technology with no moving mechanical parts, it accurately measures instantaneous flow, cumulative flow, velocity and working parameters of flare gas and mixed vent gas. It serves as the core intelligent instrument for flare gas emission metering, environmental monitoring, process energy consumption statistics and vent condition management.
As a customized high-end version, this model integrates OIM metering certification, enhanced I/O modules, explosion-proof structure and multi-protocol communication interfaces. It adapts to complex mixed flare gas measurement scenarios and is barely affected by slight fluctuations of gas pressure, temperature and components. With no blockage, no wear and no pressure loss, it supports ultra-low and ultra-high velocity measurement, adapting to continuous venting, intermittent venting and variable-load venting working conditions. It is widely used in chemical refining, oil and gas production, cogeneration parks for environmental compliance monitoring and energy metering.
2. Technical Features
2.1 Loss-Free & Maintenance-Free Ultrasonic Measurement
Based on high-precision ultrasonic transit-time principle, the meter has no impeller, orifice plate or mechanical moving parts, completely eliminating wear, blockage, stagnation and excessive pressure loss of traditional flowmeters. It does not interfere with the pipeline flow field without medium pressure loss, perfectly adapting to low-pressure, large-diameter and low-velocity flare gas vent conditions. No disassembly cleaning or regular calibration is required for long-term operation, greatly reducing on-site maintenance workload and operating costs.
2.2 Ultra-Wide Range Measurement for Full-Condition Venting
It features an extremely wide velocity measuring range of 0.03～120m/s bidirectional flow, covering full flare gas working conditions including micro-leakage, conventional venting and emergency large-flow venting. Compatible with large-diameter pipelines up to 3m, it matches the size and working characteristics of main and branch flare vent pipelines with no measurement blind zone.
2.3 Adaptive Gas Algorithm with Stable Precision
Equipped with exclusive flare gas adaptive measurement algorithm, it automatically adapts to mixed gases such as methane, ethane and propane, and compensates measurement errors caused by temperature, pressure and component fluctuations. It delivers high measurement accuracy and repeatability without long-term drift, supporting accurate flare gas emission metering, environmental data traceability and process energy consumption statistics to meet high-standard industrial metering and compliance requirements.
2.4 Explosion-Proof & Corrosion-Resistant Industrial Protection
Adopting epoxy-coated aluminum explosion-proof housing with IP66/Type4X all-weather protection, it is dustproof, waterproof, anti-corrosion and anti-aging. Certified with Class I Division 2 explosion-proof standard, it adapts to harsh environments such as flammable and explosive atmosphere, high humidity, dust and corrosive gas in chemical and oil-gas stations, supporting long-term outdoor all-weather continuous operation.
2.5 Modular I/O & Multi-Protocol Communication
Adopting modular architecture, it is equipped with isolated analog input/output and frequency signal interfaces for multi-channel signal collection and output. Integrated with HART and RS232 protocols, it supports optional Modbus RS485, Ethernet and OPC expansion interfaces. It seamlessly connects with DCS and PLC systems to realize real-time data upload, remote parameter configuration and online condition monitoring, adapting to intelligent factory automatic control networking.
2.6 OIM Certified for Full Compliance & Traceability
Built-in OIM standardized metering certification module ensures measurement data complies with industrial trade metering and environmental monitoring standards. With authoritative calibration and complete data traceability, it is applicable to factory flare gas emission accounting, environmental verification, energy settlement and process parameter calibration.
2.7 Intelligent Self-Diagnosis & Fault Early Warning
Automatic power-on self-test and full-time real-time monitoring of ultrasonic signal quality, pipeline conditions, communication status and module faults. It accurately identifies hidden risks such as signal abnormality, no medium, module failure and communication interruption, actively outputs alarm information and supports fault code tracing for rapid on-site troubleshooting, ensuring continuous and stable flow monitoring.
3. Detailed Specifications
3.1 Basic Hardware Parameters
- Model: XGF8681-21-OIM-34-0
- Manufacturer: Baker Hughes Panametrics (USA)
- Device Type: Industrial Flare Gas Ultrasonic Mass Flowmeter
- Measurement Principle: Ultrasonic Transit-Time Technology
- Housing Material: Epoxy-Coated Aluminum Alloy
- Protection Grade: IP66 / Type4X All-Weather Protection
- Explosion-Proof Grade: Class I Division 2 Certified
- Structural Features: Modular Plug-In Structure, Compact Explosion-Proof Housing, Outdoor Weatherproof Design
- Core Functions: Instantaneous/Cumulative Flare Gas Flow Measurement, Bidirectional Velocity Monitoring, Working Parameter Collection, Data Remote Transmission, Fault Self-Diagnosis, Compliant Metering
3.2 Measurement Performance Parameters
- Velocity Range: 0.03～120 m/s (Bidirectional Measurement)
- Applicable Pipe Diameter: Max 3000mm (120 inch) Large-Diameter Pipeline
- Measurable Medium: Flare Gas, Natural Gas, Alkane Mixed Vent Gas, Industrial Waste Mixed Gas
- Measurement Characteristics: No Pressure Loss, No Blockage, No Wear, Adaptive Gas Component Fluctuation
- Turndown Ratio: Ultra-Wide Range, Covering Full Working Conditions from Micro Flow to Large Flow
- Stability: Zero Drift Free for Long-Term Operation, Minimal Repeatability Error
3.3 Signal & Interface Parameters
- Analog Output: 2 Isolated 4～20mA Outputs, Max 600Ω Load
- Analog Input: 2 Isolated 4～20mA Inputs, 24VDC Loop Powered
- Frequency Output: Optional Optically Isolated Frequency Output, DC～10KHz, Max 100VDC/1W
- Standard Communication: RS232, HART Protocol (Integrated in 4-20mA Loop)
- Extended Communication: Optional Modbus RS485, TCP/IP Ethernet, OPC Server Interface
- Signal Performance: Multi-Stage Digital Filtering, Strong Anti-Interference, Stable Data Transmission
3.4 Electrical Power Parameters
- Power Supply: Industrial Standard 24VDC Wide Voltage Power (±10% Tolerance)
- Power Protection: Built-In Surge, ESD, Reverse Polarity and Filter Protection Circuit
- Power Consumption: Low-Power Stable Operation, No Abnormal Heating During Long-Term Operation
- Loop Power Supply: Independent 4-20mA Loop Power, Adapted to Conventional Industrial Wiring
3.5 Environmental & Mechanical Parameters
- Operating Temperature: -40℃～+60℃ for Long-Term Outdoor & Cabinet Operation
- Storage & Transit Temperature: -55℃～+75℃ for Transportation and Long-Term Storage
- Operating Humidity: 5%～95% RH (Non-Condensing), High Humidity & Condensation Corrosion Resistance
- EMC Performance: Industrial-Grade Anti-Interference Against Harmonic, RF, ESD and Surge Interference
- Mechanical Dimensions: Weight 5kg, Size 362mm×290mm×130mm, Easy Installation
- Weather Resistance: UV Resistance, Anti-Aging, Dustproof & Waterproof for Harsh Outdoor Conditions
3.6 Certification & Functional Configuration
- Metering Certification: OIM Standard Metrological Certification for Complete Compliance and Traceability
- Functional Configuration: 21 Version Basic Module, OIM Metering Module, 34 Groups of Custom Parameter Configuration
- Diagnosis Functions: Signal Quality Detection, Working Condition Abnormity Monitoring, Communication Fault Diagnosis, Parameter Alarm
- Data Storage: Real-Time Data, Historical Condition and Fault Event Recording for Traceability Analysis
4. Operating Principle
The DigitalFlow XGF8681-21-OIM-34-0 flowmeter operates based on ultrasonic transit-time principle. Installed outside the flare vent pipeline, the upstream and downstream ultrasonic transducers alternately transmit and receive high-frequency ultrasonic signals. When gas flows in the pipeline, the downstream propagation speed increases while the upstream speed decreases. The meter accurately captures the time difference between forward and reverse propagation, and calculates gas velocity, instantaneous volume flow and cumulative flow in real time through high-precision algorithms combined with pipe diameter, medium temperature and pressure compensation parameters.
During operation, the built-in adaptive compensation system continuously monitors subtle changes in gas components, ambient temperature and working pressure, dynamically corrects measurement coefficients and eliminates errors caused by environmental and medium fluctuations, ensuring stable full-condition measurement accuracy. The non-contact measurement mode causes no flow field interference or pressure loss, perfectly adapting to the low-pressure, variable-component and variable-velocity characteristics of flare gas.
Meanwhile, the meter outputs flow data in real time through modular I/O interfaces and uploads to upper control systems via HART and Modbus protocols. The full-time intelligent self-diagnosis system monitors signal quality and equipment status, triggers alarms for abnormalities, and realizes all-weather accurate monitoring, data traceability and condition control of flare gas flow.
5. Application Scenarios
5.1 Refinery Flare Gas Emission Monitoring
Widely used in flare vent systems of petroleum refining and fine chemical plants, it accurately measures vent flow of waste gas and combustible mixed gas during production, supporting environmental emission statistics, compliance verification and process vent condition monitoring to meet daily environmental supervision requirements.
5.2 Oil & Gas Station Vent Metering
Adapted to flare vent conditions of oil and gas production, gathering and natural gas treatment stations, it measures total vent gas volume during equipment maintenance pressure relief, emergency pressure relief and daily micro-venting, realizing accurate energy loss statistics and refined production management.
5.3 Cogeneration & Industrial Park Waste Gas Monitoring
Applied in centralized vent systems of thermal power plants and industrial parks to monitor waste gas emission flow of gas turbine units and process equipment, providing accurate data support for energy consumption accounting, environmental ledgers and production optimization, adapting to industrial intelligent management systems.
5.4 Trade Metering & Energy Settlement
With authoritative OIM metering certification, it is applicable to energy settlement, loss metering and process calibration of flare gas and waste combustible gas, providing traceable and high-precision data for industrial trade metering and internal energy accounting.
