Hongnuo (shenyang) General Machinery Co., Ltd. is one of the most reliable manufacturers and suppliers of gear type flow meter in China. Welcome to buy high quality gear type flow meter at competitive price from our factory. We also accept customized orders.
What makes it different
While turbine and vortex flow meters perform well in many general-purpose applications, gear flow meters are often the preferred choice for low-flow and high-viscosity processes. The positive displacement principle used by the HNF30 provides excellent repeatability and reliable performance in applications such as oils, resins, adhesives, and precision dosing systems, where measurement consistency is critical.
What it handles
Liquids with some viscosity.
The sweet spot is 5 to 500 mm²/s.Think diesel, hydraulic oil, lubricating oil, light fuel oils, and some chemical fluids that don't attack the materials.
It doesn't care what pump you're using – centrifugal, peristaltic, diaphragm – it works downstream of any of them.But it's not for water. Water is too thin – accuracy drops. If you're metering water, we have other models.
This one is for oils.Also, don't use it with aggressive corrosive media unless you select the 316L or PTFE version. Just tell us what you're handling, and we'll spec the right materials.
Where it's used
Lube oil monitoring – On compressors, turbines, and large rotating equipment. Track oil consumption or detect leaks early.
Hydraulic systems – Test rigs, press lines, and mobile equipment. Accurate flow data for performance validation and predictive maintenance.
Fuel transfer and dispensing – Diesel and light fuel oil metering in depots, generator sets, and marine applications.
Chemical dosing and blending – Precise additive injection where consistency matters.
Skid-mounted systems – OEM packages for lubrication, fluid handling, and test equipment.
Core specs
| Parameter | Value |
|---|---|
| Flow range | 0.6 – 20,000 L/h (model dependent) |
| Accuracy | ±0.5% of reading (1:20 turndown) |
| Viscosity range | 5 – 500 mm²/s |
| Pressure rating | Aluminium 50 bar / SS 100 bar (custom up to 400 bar) |
| Medium temperature | -40°C … +80°C (standard) / +200°C (high-temp option) |
How it works - short version
Fluid enters the chamber and pushes two precision gears. Each gear tooth gap traps a fixed, known volume of liquid. As the gears rotate, the chambers fill and empty repeatedly. A non-contact sensor picks up each gear tooth passing by and generates a pulse. The transmitter counts the pulses and calculates total flow.
The formula is as simple as it gets:
Q = V × N
(Flow = fixed volume per rotation × number of rotations)
No complex algorithms. No correction factors. Just counting.
Ordering - what we need to know
Four questions, and we'll spec the right unit for you:
- What's your flow range? Pick from: 0.6‑50, 5‑250, 10‑500, 20‑1200, 200‑3000, 1000‑12000, or 2000‑20000 L/h.
- What's your fluid? We need to know viscosity, temperature, and any corrosive properties.
- What connection type? Thread, flange, sanitary clamp, or card sleeve.
- What output signal? Pulse, analogue (4‑20mA), or RS485.
Send us your process conditions. We'll confirm the right configuration - materials, seals, bearings, and pressure rating.
| HNF30 Gear Flow Meter Specifications | |
| Specific Parameters | Value / Description |
| Measurement Principle | The HNF30 gear flowmeter is a high-precision positive displacement flowmeter. Its working principle utilizes the pressure difference generated at the inlet and outlet when the fluid passes through the flowmeter, driving a pair of precision meshing gears to rotate inside a closed chamber. Each gear forms a fixed volume 'measuring chamber' between the gear root and the chamber. With each rotation of the gear, the fluid is divided into multiple known volume units and counted, thereby accurately calculating the total fluid volume through the cumulative number of rotations, achieving high-precision flow measurement. |
| Nominal Diameter Range | DN8 ~ DN32 (corresponding to thread specifications G1/4 ~ G1-1/4) |
| Wetted Parts Material | Body: 304 stainless steel, 316L stainless steel, aluminum alloy; Gear: 304 stainless steel, 316L stainless steel, high hardness alloy steel; Bearings: rolling bearings or sliding bearings; Seals: FKM, NBR, PTFE. |
| Connection Method | Threaded connection (G series), flange connection (optional for national standard, American standard, Japanese standard), clamp connection, sanitary clamp connection available. |
| Maximum Measurement Error | ±0.5% of reading (within 1:20 range ratio), ±1% of reading (full range). |
| Measurement Range | 0.6 ~ 20000 L/h (corresponding to models HNF30-02 ~ HNF30-32/40). |
| Maximum Process Pressure | Aluminum alloy body: 5 MPa (50 bar); Stainless steel body: 10 MPa (100 bar); Customizable up to 40 MPa (400 bar). |
| Medium Temperature Range | Standard: -40 ~ +80 °C; High temperature customization: up to +200 °C. |
| Ambient Temperature Range | -40 ~ +85 °C |
| Transmitter Housing Material | Cast aluminum alloy or stainless steel (depending on the body material). |
| Display/Operation | Optional local display (yes/no), supports local instantaneous and cumulative flow display. |
| Inputs | 24VDC |
| Outputs | Pulse frequency (up to 5 kHz), analog (4-20mA, 1-5V, 2-10V), RS485 (Modbus-RTU), HART, GPRS, Bluetooth. |
| Power Supply | 9-26 VDC |
| Certificate | Explosion-proof: Exd IIC T6 Gb; Protection level: IP65. |
