Rotary piston flow meter NB

volumefor gasfor natural gas

Overview
YUNYI NB wireless Roots flow meters (rotary gas meters) are volumetric gas measurement instruments designed for high-precision, repeatable metering. They integrate flow, temperature and pressure measurement with automatic temperature and pressure compensation and display cumulative volume at standard conditions.

Operating Principle
The meter uses a pair of precision-machined conjugate rotors (Roots lobes) that rotate alternately under the differential pressure between inlet and outlet. Each full rotor revolution displaces a defined gas volume (four times the effective metering chamber per revolution). A magnetic sealed coupling and a reduction mechanism transmit rotor rotations to the totalizer for accurate cumulative volumetric calculation and display.

Product Advantages and Features

• Measurement performance: High accuracy (up to ±1.0%), excellent repeatability and wide turndown ratio (up to 1:216). Very low starting flow enables accurate measurement across large load variations.
• Smart and wireless communication: Ultra-low-power electronics and microcontroller-based design enable extended battery operation. Optional communication modules (GPRS/CDMA), RS-485 interface or DTU enable remote data transmission and centralized monitoring.
• Robust design and compact installation: No requirement for long straight pipe runs upstream or downstream; suitable for confined spaces. Fully sealed enclosure with IP65 protection and intrinsically safe explosion-proof certification (ExiaⅡCT4).
• Data and diagnostics: Onboard historical data storage, self-diagnostic features and alarm outputs (e.g., low battery alerts) to support maintenance and asset management.

Application Areas

• Urban gas and energy metering: natural gas transmission and distribution, gas regulating stations, commercial billing (restaurants, hotels), residential boiler metering.
• Petrochemical and industrial processes: oilfields, petrochemical plants, metallurgy, power generation — suitable for non-corrosive gases such as industrial inert gases, coal gas, natural gas and biogas.
• Environmental and energy-recovery projects: flow monitoring for biogas utilization and other energy-recovery systems.

Specifications

• Measurement principle: Volumetric (Roots / rotary gas meter)
• Accuracy: up to ±1.0%
• Repeatability: high
• Turndown ratio: up to 1:216
• Starting flow: extremely low (suitable for wide load variation)
• Integrated measurements: flow, temperature and pressure with automatic compensation
• Rotor signal transmission: magnetic sealed coupling + reduction mechanism to totalizer
• Power: Ultra-low-power design; battery operation (typical battery life >5 years, depending on configuration and usage)
• Communication options: optional GPRS/CDMA modules, RS-485 interface, DTU module for wireless remote transmission
• Enclosure/protection: fully sealed design, IP65
• Safety certification: intrinsically safe explosion-proof (ExiaⅡCT4)
• Installation: no long straight-pipe requirement upstream/downstream; suitable for confined installations
• Data functions: onboard historical data storage, self-diagnostics and alarm functions (e.g., low battery alert)