How to Choose a Diesel Fuel Flow Meter for Your Application

How to Choose the Right Diesel Fuel Flow Meter

Choosing the right diesel fuel flow meter depends on four key factors: your flow rate, connection size, whether you need a mechanical or digital readout, and your specific application. This guide walks you through each factor so you can pick the best diesel flowmeter for your setup — whether that's a farm fuel tank, a generator, a fuel depot, or a boat engine.

Step 1: Determine Your Flow Rate

The most important specification for any diesel fuel meter is its flow range — measured in litres per minute (LPM) or litres per hour (LPH). Using a meter outside its rated range causes inaccurate readings and premature wear.

Here's a general guide to flow rates by application:

Step 2: Mechanical vs Digital (Pulse Output) Meters

There are two main types of diesel fuel flow meters:

Mechanical Diesel Flow Meters

Mechanical meters like the OGM-25, OGM-40, and OGM-50 use oval gears to measure flow and display the total on a 4-digit mechanical counter. They are the best choice when you need:

• An easy-to-use fuel meter with no wiring or setup
• A diesel flowmeter for remote locations with no power supply
• A simple, good quality flowmeter for visual fuel tracking
• Low maintenance with no electronics to fail

Digital (Pulse Output) Diesel Flow Meters

Pulse output meters like the OGM-15P and the Positive Displacement Flow Meter output electrical pulses proportional to flow. They are the best choice when you need:

• Integration with PLCs, SCADA, or batch controllers
• Automated diesel fuel consumption monitoring
• Data logging for fleet management or compliance
• Diesel batching measurement for controlled dispensing

Step 3: Consider Your Fluid Type

Oval gear flow meters are ideal for viscous fluids. They accurately measure:

• Diesel fuel — the most common application
• Engine oil and lubricating oil — perfect as an oil flow meter for workshops
• Hydraulic oil — suited for industrial oil flow measurement
• Kerosene and heating oil — common in rural Australia

Important: Oval gear diesel flow meters are NOT suitable for water, petrol (gasoline), solvents, or corrosive chemicals. For these fluids, a different meter technology (turbine or electromagnetic) is required.

Step 4: Match the Meter to Your Application

Farm Fuel Tanks and Bowsers

For most farm diesel fuel measurement, the OGM-25 (1" BSP, 20–120 LPM) is the best choice. It's easy to install, requires no power, and gives you accurate fuel consumption tracking for tractors, harvesters, and utes.

Generators and Stationary Engines

For generator fuel consumption monitoring, match the meter size to your generator's fuel consumption rate. Most generators under 500kVA use the OGM-40 (1.5" BSP, 25–250 LPM). For larger generators or where you need data logging, use a pulse output flow meter connected to your building management system.

Fuel Depots and Bulk Transfer

For high-volume diesel fuel measurement at fuel depots, mining sites, and bulk storage, the OGM-50 (2" BSP, 30–300 LPM) handles the highest flow rates. For diesel batching measurement with automated shutoff, pair a pulse output meter with a batch controller.

Marine and Boat Engines

For boat engine fuel consumption monitoring, the OGM-15P (1/2" BSP, 1–30 LPM) is purpose-built. Its 100 pulses-per-litre output integrates with marine fuel displays to track engine fuel burn per trip.

Why Choose an Oval Gear Diesel Flow Meter?

Oval gear (positive displacement) meters are the industry standard for diesel fuel measurement because:

• ±0.5% accuracy across the full flow range — no recalibration needed
• Works with viscous fluids — actually gets more accurate as viscosity increases
• No straight pipe requirements — install in tight spaces without upstream/downstream runs
• Bidirectional measurement — useful for supply/return line setups
• Long service life with minimal moving parts and aluminium construction

Buy a Diesel Flow Meter in Australia

RAZQUIP is a Sydney-based supplier of diesel fuel flow meters, shipping Australia-wide. Every meter ships with a calibration certificate and is backed by local Australian support. Browse our full range of commercial and industrial flow meters or marine flow meters, or contact our team for sizing assistance.