Marine Fuel Oil Flowmeter Selection Guide

I. Measurement Media

Marine fuel metering primarily covers two media: HFO (Heavy Fuel Oil) and MGO (Marine Gas Oil). The two differ markedly in viscosity: MGO is approximately 2–6 cSt, while HFO can reach up to 700 cSt (at 50 °C). This wide viscosity span is the core constraint governing instrument selection.

II. Meter Type Selection

For the wide-viscosity operating conditions described above, both oval gear flowmeters and helical rotor flowmeters deliver excellent adaptability and are the recommended meter types for this application.

When selecting an oval gear flowmeter, the following three points require attention:

1. Select the marine version, which offers an extremely wide turndown ratio and a minimum flow rate as low as 10 L/H, covering small-flow conditions such as low main engine load and in-port manoeuvring;
2. Select the high-temperature version to suit the high-temperature operating conditions of HFO, with an applicable temperature range of up to 200 °C;
3. Display options: mechanical display or LCD display.

III. Signal Output

Output signals are available as pulse output or switch (contact) signal output, and can be connected directly to the ship’s monitoring system or a secondary display instrument.