1. What Is a Gas Roots Flow Meter? Industry Introduction
A Gas Roots Flow Meter (also called a Roots Gas Flow Meter or Rotary Gas Flow Meter) is a positive displacement volumetric metering instrument that uses two synchronized roots-type rotors (waist wheels) to measure the volume of non-corrosive gases passing through a pipeline. As the rotors rotate in precise synchronization driven by the gas flow itself, each rotation displaces a fixed, known volume of gas. By counting rotations, the meter calculates cumulative and instantaneous gas volume with high accuracy — independent of the incoming flow velocity profile.
This measurement principle makes the Gas Roots Flow Meter particularly valuable in industrial and commercial gas measurement, where billing accuracy, custody transfer, and process control depend on stable, repeatable volumetric data. Unlike differential-pressure or turbine-based instruments, roots-type meters do not require long straight pipe sections upstream and downstream, simplifying installation in space-constrained facilities.
Why accurate gas measurement matters:
- Commercial settlement between gas suppliers and end users depends on precise volumetric data.
- Industrial processes (boilers, burners, chemical reactors) require stable gas input for safety and efficiency.
- Regulatory and metrological compliance (e.g., JJG 633, GB/T 28848, OIML R6) requires certified accuracy classes.
- Temperature and pressure fluctuations in gas networks can distort raw volumetric readings, requiring compensation.
Industries commonly requiring gas flow measurement:
- Urban gas transmission and distribution networks
- Catering and hotel industries (commercial kitchen gas billing)
- Industrial boiler and burner systems
- Civil/residential heating systems
- LPG and fuel gas distribution
- Chemical and industrial gas processing plants
2. Gas Roots Flow Meter Product Overview
Working Principle
The Gas Roots Flow Meter operates on volumetric displacement: two roots-shaped rotors, linked by synchronous gears, rotate as gas passes through the meter body. Each full rotation cycle isolates and displaces a fixed gas volume. This mechanical measurement is independent of flow profile distortion, meaning no straight pipe run is required before or after the meter — a significant installation advantage over turbine or vortex meters.
Product Structure
- Meter body housing with roots-wheel rotor assembly and synchronous gear drive
- Mechanical counter and/or electronic display head (rotatable up to 350° for flexible orientation)
- Integrated or external temperature/pressure sensors for volume correction
- Microprocessor-based volume correction instrument (for electronic models)
- Explosion-proof electrical housing (Exia II CT4Ga) for hazardous area compliance
Measurement Characteristics
- Rangeability: up to 160:1 or higher, covering both pilot-light-level low flow and peak industrial demand
- Starting flow: less than 0.02 m³/h, enabling detection of minimal gas consumption
- Accuracy class: 1.0 and 1.5
- No influence from flow velocity profile — suitable for installation without straight pipe requirements
- Supports horizontal and vertical installation orientations
Technical Advantages
- Automatic compression factor correction (based on SY/T 6143-2004 or SGERG-88 standards) via integrated PV/T gas equation processing
- Intrinsically safe explosion-proof design (Exia II CT4Ga) with IP66 ingress protection
- Multiple signal outputs: RS-485 (MODBUS RTU protocol), pulse output, and optional 4-20mA analog signal
- Onboard data logging capacity of at least 8,000 flowmeter status records
- 5-year continuous internal battery life for uninterrupted metering
- Optional mechanical-electronic dual display for data redundancy during power loss
Suitable Operating Conditions
Gas Roots Flow Meters are designed for non-corrosive gases including natural gas, city gas, propane (LPG), nitrogen, and carbon dioxide. Flange connection sizes typically range from DN20 to DN200, supporting a wide range of pipeline diameters in commercial and industrial installations.
Gas Roots Flow Meter vs. Other Gas Flow Meters
- Vs. Turbine Flow Meters: Roots meters do not require straight pipe sections and perform better at low flow rates and startup conditions.
- Vs. Vortex Flow Meters: Roots meters provide more stable readings at low velocities, where vortex meters may lose signal reliability.
- Vs. Electromagnetic Flow Meters: Roots meters are purpose-built for gas media (electromagnetic meters are primarily for conductive liquids).
- Advantage summary: Positive displacement design offers high accuracy across a wide rangeability window without dependency on flow conditioning.
3. Application and Industry Solutions
Natural Gas Measurement
- Customer requirement: Accurate volumetric billing across fluctuating pressure and demand cycles in transmission and distribution networks.
- Challenge: Temperature and pressure variations can distort raw volume readings, affecting billing accuracy.
- Recommended characteristics: Integrated temperature/pressure compensation, PV/T correction, wide rangeability (up to 160:1).
- Selection consideration: Choose accuracy class (1.0 or 1.5) based on custody-transfer or commercial billing requirements.
LPG Gas Flow Measurement
- Customer requirement: Reliable metering of liquefied petroleum gas in distribution and cylinder-filling operations.
- Challenge: LPG systems often require explosion-proof equipment due to hazardous area classifications.
- Recommended characteristics: Intrinsically safe electrical design (Exia II CT4Ga), IP66 protection grade.
- Selection consideration: Confirm compatibility of meter materials and seals with LPG media properties.
Industrial Gas Measurement
- Customer requirement: Stable measurement for boiler feed gas, burner systems, and process gas lines under variable working conditions.
- Challenge: Working condition flow must be converted to standard volume for process control and reporting.
- Recommended characteristics: Onboard PV/T correction instrument for real-time standard volume conversion.
- Selection consideration: Verify meter accuracy class aligns with process tolerance requirements (e.g., ±1.0%).
Fuel Gas Measurement
- Customer requirement: Consistent metering for fuel gas supply to heating and combustion equipment.
- Challenge: Fuel gas installations often have limited power infrastructure.
- Recommended characteristics: Mechanical-only (HRM) or dual-display (HRS) options for power-independent operation.
- Selection consideration: Evaluate whether mechanical backup is mandatory per site regulations.
Energy Management
- Customer requirement: Centralized monitoring of gas consumption across multiple sites or meters.
- Challenge: Manual data collection is inefficient for large-scale energy management programs.
- Recommended characteristics: IoT wireless module (GPRS, Cat1, NBIoT) with cloud platform integration.
- Selection consideration: Confirm communication protocol compatibility with existing energy management software.
Commercial Gas Distribution
- Customer requirement: Prepaid gas control for commercial and industrial customers, reducing collection risk.
- Challenge: Manual fee collection is labor-intensive and prone to arrears.
- Recommended characteristics: Intelligent IC Card Prepayment System with zero-pressure-loss valve and automatic shutoff on credit exhaustion.
- Selection consideration: Confirm maximum prepaid gas purchase capacity matches customer consumption scale.
4. Manufacturer Selection Guide: How to Choose a Reliable Gas Roots Flow Meter Manufacturer
International buyers evaluating a Gas Roots Flow Meter Manufacturer or Gas Roots Flow Meter Supplier should assess the following factors:
- Manufacturing capability: Does the manufacturer produce the core roots-wheel rotor assembly in-house, ensuring consistent synchronous gear precision?
- Product design capability: Does the manufacturer hold independent intellectual property rights over the flow meter structure, supporting long-term stability and assembly repeatability?
- Quality control system: Are there enterprise standards (such as Q/HD 003-2023 "Gas Roots Flowmeter") governing production consistency?
- Testing and inspection process: Does the manufacturer provide Product Type Test Certificates issued by recognized metrology authorities?
- Calibration capability: Can the manufacturer demonstrate compliance with verification regulations such as JJG 633 "Gas Positive Displacement Flowmeter"?
- Technical support: Does the manufacturer offer pre-sales specification selection, installation guidance, and after-sales troubleshooting manuals?
- Customization capability: Can the manufacturer configure electronic, mechanical, or dual-display models, IC card prepayment, and IoT communication options to match project needs?
- International export experience: Does the manufacturer’s product line comply with international standards such as OIML R6, enabling global market compatibility?
Buyers should also verify explosion-proof certification (e.g., Exia II CT4Ga) and ingress protection rating (e.g., IP66) when sourcing meters for hazardous area applications.
5. Manufacturer Capability and Trust Building: Kaifeng Xinya Instrument Co., Ltd.
Kaifeng Xinya Instrument Co., Ltd., operating under the Xinya Instrument brand, is a specialized manufacturer of volumetric gas metering solutions headquartered in Kaifeng Demonstration Area, Henan, China. The company focuses on high-precision Gas Roots Flow Meters integrating intelligent electronic display, mechanical backup, and IoT-enabled prepayment systems for urban gas management.
Manufacturing Background and R&D Capability
Xinya Instrument has developed a proprietary roots-wheel structure with independent intellectual property rights, engineered for improved production assembly consistency and long-term operational stability. The company maintains an Intelligent IC Card Prepayment System and IoT Cloud Platform technology stack to support remote gas management applications.
Quality Management and Certifications
Xinya Instrument’s products and processes are governed by the following verified standards and certifications:
- GB/T 28848 "Intelligent Gas Flowmeter" National Standard Compliance
- Q/HD 003-2023 "Gas Roots Flowmeter" Enterprise Standard
- JJG 633 "Gas Positive Displacement Flowmeter" Verification Regulation
- OIML R6 International Standard
- JB/T 7385 "Gas Waist Wheel Flowmeter" Industry Standard
- Explosion-proof Certification: Exia II CT4Ga
- Protection Grade: IP66
- Product Type Test Certificates: No. 2017F103-35 (obtained 2017) and No. 2023F129-35 (obtained 2023)
Product Portfolio
Xinya Instrument’s Gas Roots Flow Meter series includes:
- HR Series: Electronic single-display type with automatic temperature/pressure compensation and RS485/pulse/4-20mA signal outputs.
- HRM Series: Mechanical single-display type for power-independent, high-reliability environments.
- HRS Series: Dual display (mechanical + electronic) type providing zero data loss during power failures.
- IC Card Prepayment System (-Y Suffix): Zero-pressure-loss ball valve with prepaid credit management, supporting purchases up to 100 million m³.
- IoT Wireless Module (-W Suffix): Multi-mode communication (GPRS, NBIoT, Cat1) with cloud platform integration, including compatibility with third-party IoT platforms and WeChat applet-based remote recharge and valve control.
Technical and Service Assurance
- Rangeability up to 160:1, starting flow below 0.02 m³/h, accuracy classes of 1.0 and 1.5
- Data storage capacity of at least 8,000 flowmeter status records
- 5-year continuous battery life for internal power supply
- Flange installation from DN20 to DN200, in horizontal or vertical orientation
- Service scope covering pre-sales specification selection, installation guidance, lubrication maintenance, and metrological verification cycles (2–3 years depending on accuracy class)
Global Market Compatibility
Xinya Instrument’s compliance with OIML R6 International Standards supports global market applicability, and its product line is widely utilized across catering and hotel industries, gas transmission and distribution networks, and industrial boiler systems.
Benchmark Application Data
- A large-scale catering facility deployment using the HR-80-G100 model achieved a 160:1 rangeability, capturing flow from pilot-light levels (0.02 m³/h) to peak cooking loads, supporting accurate billing across all operating conditions.
- An industrial boiler system application converted 123.11 m³/h of working condition flow to standard volume using the integrated PV/T equation, maintaining accuracy within ±1.0%.
6. Buyer FAQ Section
Q: What is a Gas Roots Flow Meter?
A: A Gas Roots Flow Meter is a positive displacement instrument that uses two synchronized roots-wheel rotors to measure the volume of non-corrosive gas passing through a pipeline, commonly used for natural gas, LPG, city gas, and industrial gas metering.
Q: How does a Roots Gas Flow Meter work?
A: The meter’s synchronized rotors turn as gas flows through the meter body, with each rotation displacing a fixed, known gas volume. Rotation counts are converted into cumulative and instantaneous flow readings, often with temperature/pressure compensation for standard volume output.
Q: Why choose a Roots Gas Flow Meter for natural gas measurement?
A: Roots-type meters offer high accuracy across a wide rangeability (up to 160:1), require no straight pipe sections for installation, and can integrate automatic compression factor correction — making them well suited for commercial billing and network metering.
Q: How do I select a reliable gas flow meter supplier?
A: Evaluate the supplier’s manufacturing and design capability, quality control system, calibration and testing certifications (such as JJG 633 and Product Type Test Certificates), international standard compliance (such as OIML R6), and after-sales technical support.
Q: What factors should be considered when buying a Gas Roots Flow Meter?
A: Key factors include required accuracy class, rangeability, starting flow, explosion-proof and IP protection ratings, display type (electronic, mechanical, or dual), communication protocol needs, pipe size (DN20–DN200), and whether prepayment or IoT remote monitoring functions are required.
Q: What industries use Roots Gas Flow Meter?
A: Roots gas flow meters are used in urban gas transmission and distribution networks, catering and hotel industries, industrial boiler systems, civil/residential heating, LPG distribution, and chemical or industrial gas processing.
7. Next Steps for International Buyers
Buyers evaluating a Gas Roots Flow Meter Manufacturer for natural gas, LPG, or industrial gas measurement projects are encouraged to:
- Request detailed product specifications for the HR, HRM, or HRS series
- Contact Xinya Instrument’s technical engineers to discuss accuracy class, rangeability, and explosion-proof requirements for specific applications
- Discuss customization needs, including IC Card Prepayment or IoT Wireless Module integration
- Request a formal quotation based on pipe diameter (DN20–DN200) and installation orientation
Contact Information:
- Company: Kaifeng Xinya Instrument Co., Ltd.
- Email: xinya@sytcflowmeter.com
- Phone: (86) 371-23668107
- Fax: (86) 371-23668496
- Address: No. 1, Ba Qing Wu Road, Jinming Avenue South Section, Kaifeng Demonstration Area, Henan, China
https://www.sytcflowmeter.com/
Kaifeng Xinya Instrument Co., Ltd.
