4-20 mA, pulse or RS485
Output
Loop or battery
Power
Clean liquids
Fluids
Fast
Response
DEFINITION & OVERVIEW
What is a Turbine Flowmeter?
A turbine flowmeter puts a small rotor in the pipe. The liquid pushes the rotor round, and the faster the liquid moves, the faster it spins. A sensor counts the rotations and the electronics turn the count into a flow rate and a total.
It is one of the simplest and most established ways to measure a clean liquid. It is light, it responds quickly and it is highly repeatable, which is why it is a common choice for dosing, transfer and utility lines where the liquid is clean and the same flow should give the same reading every time.
John Finlay's turbine flowmeter is a velocity-type meter for clean or essentially clean single-phase liquids, measuring volumetric flow or total in a closed pipe. The two-wire version gives a 4-20 mA signal with a raw pulse output for calibration, and the three-wire version offers RS485 communication or battery operation. It is not the right tool for slurry, where a rotor and bearings would suffer. For slurry and water, see our Electromagnetic Flowmeter, and for liquids, gas and steam with no moving parts, see our Vortex Flowmeter.
Simple and Light
A rotor, a sensor and the electronics. Few parts, low weight and easy to install on a clean line.
Fast Response
The meter follows changes in flow quickly, and the same flow gives the same reading.
Wired Your Way
Two-wire 4-20 mA with a raw pulse output, or three-wire with RS485 and battery operation.
Parameter | Value |
|---|---|
Measuring Principle | Velocity-type turbine rotor |
Fluids | Clean or essentially clean single-phase liquids |
Measures | Volumetric flow or total, in a closed pipe |
Two-Wire Version | 4-20 mA, with raw pulse output for calibration |
Three-Wire Version | RS485 or battery operation |
Repeatability | High |
Response | Fast |
KEY FEATURES
Key Features & Performance Highlights of Vortex Flowmeter
Simple, Light Construction
A rotor and a sensor in a short pipe section keep the meter light and easy to handle and install.
Repeatable Reading
For dosing, transfer and batching, the repeat reading matters as much as the absolute one, and it is this meter's main strength.
Fast Response
The rotor follows changes in flow quickly, which suits batching and fast-changing lines.
Two Wiring Options
Two-wire 4-20 mA for a standard control loop, with a raw pulse output that helps when calibrating. Three-wire adds RS485 communication or battery power.
Battery Operation
The three-wire version can run on battery, for remote points where no power cable is available.
WORKING PRINCIPLE
How the Turbine Flowmeter Works
Liquid spins a rotor. The meter counts the turns.
Liquid Enters the Meter
Clean liquid flows through a short pipe section with a rotor on its axis.
The Rotor Spins
The liquid pushes the rotor round at a speed that rises with the flow velocity.
A Sensor Counts Rotations
A sensor picks up each blade as it passes, producing a pulse train.
Electronics Convert to Flow
The pulse count becomes a volumetric flow rate and a running total.
Signal Out
The result goes to the control system as 4-20 mA with a raw pulse output (two-wire) or over RS485 (three-wire).
TECHNICAL SPECIFICATIONS
Turbine Flowmeter | Full Specification
Parameter | Value |
|---|---|
Principle | Velocity-type turbine rotor |
Fluids | Clean or essentially clean single-phase liquids |
Measures | Volumetric flow or total, in a closed pipe |
Two-Wire Version | 4-20 mA, with raw pulse output for calibration |
Three-Wire Version | RS485 or battery operation |
COMPARISON
Turbine Flowmeter
Vortex Flowmeter
Applications of the Turbine Flowmeter
Clean liquid lines where repeatability and a simple installation matter.
Clean Water Lines
Measures clean process or utility water in a closed pipe.
Dosing and Transfer
Repeatable readings for dosing, batching and transfer of clean liquids.
Batch Totalizing
Volumetric total from the pulse output for batch duty.
Remote Points
Battery operation on the three-wire version where no power is nearby.
Slurry and dirty liquids suit non-contact designs
see our Electromagnetic Flowmeter and Non-Full-Pipe Electromagnetic Flowmeter.
Which Flowmeter Do I Need? The Five-Meter Selection Table
Our flow range covers five meters. Start with the fluid, then check the line.
Meter | Best for | Fluid | Moving parts | Output |
|---|---|---|---|---|
Small, repeatable reagent and dosing volumes | Clean liquids | Matched gears | 4-20 mA, pulse, RS485 Modbus-RTU | |
Turbine Flowmeter | Clean liquid lines where repeatability and a simple installation matter | Clean liquids | Rotor | 4-20 mA with pulse, or RS485 |
Vortex Flowmeter | Gas, steam and hot lines, or any line where no moving parts are wanted | Liquids, gases and steam | None | Pulse or 4-20 mA |
Conductive slurry and water in full pipes | Conductive liquids and slurry | none | 4–20 mA and RS485 | |
Partly filled lines | Conductive liquids | None | 4–20 mA (load ≤ 500 Ω) |
About John Finlay
Flow Instrumentation Supplier in India
Why John Finlay?
Simple
Light, Quick, Repeatable
A rotor, a sensor and the electronics, for clean liquid lines.
130+
Coal Washery Projects
Completed EPC projects worldwide, including Asia’s largest coking coal washery at 30 MTPA.
EPC
Full Circuit Supply
Supplied as part of a complete instrumentation and automation offering across the coal preparation flowsheet.
IN
India-Based Support
Manufactured at Hefei John Finlay Mining Equipment Co., Ltd. and supported locally in India for installation, commissioning, spares and service.
Turbine Flowmeter | Frequently Asked Questions
Common questions from process engineers choosing a flowmeter for clean liquids.
Liquid pushes a rotor round at a speed that rises with flow velocity. A sensor counts the rotations and the electronics convert them to flow rate and total.
Clean or essentially clean single-phase liquids in a closed pipe. It is not for slurry, where a rotor and bearings would be damaged.
The two-wire version gives 4-20 mA with a raw pulse output for calibration. The three-wire version offers RS485 communication or battery operation.
Repeatability is its main strength, which is why it suits dosing and batching.
Turbine meters generally need clean liquid and a straight pipe run before and after the meter for a steady flow profile.Â
Use a turbine meter for clean liquid lines where repeatability and a simple installation matter. Use our Micro Gear Flowmeter for small dosing volumes, our Vortex Flowmeter for gas, steam and hot lines, and our Electromagnetic Flowmeter for conductive slurry and water.
Need a repeatable reading on a clean liquid line?
Our engineers can help you choose the right meter for each line.
Talk to an ExpertRelated Equipment
Turbine Flowmeter
For clean single-phase liquids where repeatability matters.
Electromagnetic Flowmeter
For conductive slurry and water lines.
Non-Full-Pipe Electromagnetic Flowmeter
For partly filled lines.
Instrumentation Overview
All instruments, including the General Instrumentation section.
Vortex Flowmeter
No moving parts for liquids, gases and steam.