Positive displacement flow meter YYCL

volumegreasefor fuel

Overview
YUNYI circular gear flowmeter is a positive displacement (volumetric) meter designed for accurate measurement of medium- to high-viscosity, particle-free liquids. It uses two precision-machined circular or oval gears that mesh and rotate inside a metering chamber, creating fixed sealed cavities. Each gear rotation transfers a fixed fluid volume; detecting rotations yields cumulative and instantaneous flow with high repeatability.

Product Advantages

• Measurement accuracy: volumetric principle with typical accuracy ±0.5% R, selectable variants down to ±0.2% R.
• Suited to high-viscosity fluids: accuracy maintained or improved at higher viscosities due to reduced internal leakage.
• No strict straight-run requirement: accuracy insensitive to upstream/downstream pipe runs, enabling compact installations.
• Wide turndown: typical ratios 10:1 to 20:1, up to 100:1 in some configurations.
• High-pressure capability: mechanical design suitable for pipeline pressures from 1.0 up to 40 MPa (design dependent).
• Multiple outputs and connectivity: pulse, 4-20 mA, RS485 and support for protocols such as HART/Modbus for PLC/DCS/SCADA integration.

Core Application Areas

• Petrochemical: custody transfer, process control for crude oil, fuel oil, lubricants, asphalt, resins.
• Food & Beverage: sanitary quantitative filling and dosing for syrups, oils, chocolate, honey, dairy.
• Chemical & Coatings: precise metering and batching of solvents, paints, inks, adhesives.
• Pharmaceutical: controlled addition and transfer of pharmaceutical solutions, glycerin and culture media.
• Laboratory & Precision: R&D, online calibration, reference metering.

Comparison — Oval/Circular Gear Meter vs Roots/Lobe Meter
Feature — Oval/Circular Gear Meter — Roots/Lobe Meter
Rotor design — Two meshing oval/circular gears (contact) — Two or three lobed rotors (non-contact)
Fluid contact — Gears contact and are lubricated by process fluid — Rotors operate with clearance, no contact
Best for — Medium to very high viscosity, lubricating liquids — Lower viscosity liquids, clean gases and some liquids
Pressure drop — Higher, increases with viscosity — Generally lower
Maintenance — Higher attention with abrasive fluids due to gear contact — Often lower for clean media

Key FAQs (summary)

• What is it? — A positive displacement flowmeter using two meshing oval or circular gears; each rotation transfers a fixed volume.
• Main benefits — High accuracy and repeatability, suited to high-viscosity liquids, good low-flow performance and broad turndown.
• Suitable media — Particle-free high-viscosity liquids (hydraulic oil, greases, asphalt), lubricants (diesel, biodiesel), chemicals and food-grade syrups. Not suitable for abrasive slurries, non-lubricating fluids without adaptation, or gases without specific design and filtration.
• Integration — Provides pulse, 4-20 mA, RS485 and supports HART/Modbus for PLC/DCS/SCADA and batch controllers.
• Installation & maintenance — Keep pipe full (horizontal preferred with shaft horizontal), fit upstream coarse strainer (eg. 100 mesh), consider heat tracing for cold/high-viscosity service, use bypass or dual meters for very wide ranges; periodic filter maintenance and calibration recommended.

Technical Specifications

• Measurement principle: Positive displacement (oval/circular gear)
• Accuracy: ±0.5% R typical; can reach ±0.2% R
• Nominal sizes (DN): DN2, DN4, DN6, DN10, DN15, DN25, DN32
• Connections: threaded, clamps, flanges, tri-clamp
• Outputs/communication: pulse, 4-20 mA, RS485; supports digital protocols (HART, Modbus)
• Materials: 304 stainless steel, PP, aluminum alloy (variants available)
• Turndown: up to 1:100 (typical 10:1 or 20:1)
• Pressure rating: 1.0–40 MPa (model dependent)
• Operating temperature: -196 °C to 170 °C
• Suitable media: particle-free liquids, high-viscosity liquids
• Display: LCD (instantaneous + cumulative flow)
• Typical uses: custody transfer, batching, filling, dosing and high-precision process control in petrochemical, food & beverage, chemical, pharmaceutical and laboratories