While Mass Flow Meters have significantly improved transparency and accuracy in bunker deliveries, experience shows that they are not immune to misuse, writes Alvin Forster, Senior Loss Prevention Executive – Americas & UK of global marine insurer NorthStandard:

Bunker quantity disputes remain one of the most frequent and contentious causes of claims and charterparty disputes. Traditional measurement methods based on tank soundings, ullage measurements and calibration/sounding tables have long been criticised for susceptibility to error and manipulation. In response, some of the major bunkering ports have mandated the use of Mass Flow Meters (MFMs) as the primary means of measuring the quantity transferred.

MFMs have significantly improved transparency and accuracy, but experience has shown that they are not immune to misuse or deliberate manipulation. Recent enforcement actions, most notably in Singapore, demonstrate that unscrupulous suppliers may attempt to defeat even sophisticated measurement systems.

Singapore pioneered the mandatory use of MFMs. Since 1 January 2017, MFMs have been compulsory for the delivery of marine fuel oil in the Port of Singapore, with the delivered quantity on the Bunker Delivery Note (BDN) derived exclusively from the MFM totaliser.

The regime has continued to evolve. From 1 April 2025, Singapore mandates compliance with SS 648:2024, which tightens requirements around data security, system integrity, piping arrangements, certification, and the use of data loggers and edge devices, reflecting lessons learned from earlier enforcement cases.

Mass appeal for MFMs

From 1 January 2026, MFMs have also been made mandatory on bunker vessels delivering fuel oil, diesel and biofuels at the ports of Rotterdam and Antwerp‑Bruges. The systems must be certified and broadly aligned with ISO 22192, mirroring the Singapore model. The use of MFMs is mandatory across port terminals in Türkiye and at the Port of Ceuta in the Gibraltar Strait, while they are also used in Gibraltar by yacht bunker supplier CEPSA, and others.    

These developments signal a significant shift in the European bunker market, which has traditionally been reliant on shore tank measurements and barge gauging.

Elsewhere, Sohar Port and Freezone have introduced measures that effectively mandate the use of MFMs for bunker supplies. Hong Kong is also looking to introduce regulations that mandate their use, but only for methanol.

Further afield, an increasing number of suppliers are adopting the use of MFMs in ports and hubs where there is no mandate.

Locations where MFMs are currently used on a non-mandatory basis include Fujairah, Zhoushan, Busan, Houston and Prince Rupert (Canada).

Manipulation against the flow

Despite the broadening appeal, and the tamper‑resistant design work that has gone into MFM solutions, there have been instances that show they can still be manipulated through physical or operational interference.

The most well‑known example concerns the bunker tankers Southernpec 6 and Southernpec 7 in Singapore. Between 2016 and 2019, industrial‑strength magnets were placed on the MFM sensors to distort measurement signals, causing the meters to record more fuel than was actually delivered. The fraud resulted in buyers being cheated of over US$300,000 worth of marine fuel oil.

Another recurring manipulation method involves irregular piping arrangements between the MFM and the ship’s manifold. Investigations in Singapore revealed cases where bunker barges had connections allowing fuel to be siphoned back to barge tanks during delivery, inflating MFM readings without the receiving vessel receiving the corresponding quantity.

Such arrangements directly contravene certification requirements but may be difficult for ship crews to detect without detailed inspection.

MFMs have defined operational limits, calibrated for liquid at constant flow. When removing the final amounts from a tank, flow rates may fall outside these parameters, and risk producing unreliable readings.

Guidance for Shipowners and Operators

Despite the increased use of MFMs and the introduction of mandates in some ports, the crew of the receiving vessel should remain vigilant with respect to the way these systems can be manipulated and take measures to protect their position. As a matter of routine, crew should:

• Always take ship’s bunker tank soundings and witness barge measurements before and after bunkering, even where MFM figures are contractually binding, and retain records.
• Inspect visible sections of MFM systems, including seals, cabling, and piping.
• Request to see the MFM bunker system certificate and confirm the unit’s serial number.
• Engage reputable, experienced bunker surveyors.  
• Issue letters of protest promptly where discrepancies arise between ship calculations and MFM figures, even if suppliers refuse to countersign.
• Ensure crews are familiar with bunkering procedures and aware of common manipulation indicators.

Crew should also be aware of the limitations in accuracy when comparing tank measurements with MFM readings. Even when both measurement technologies are accurate, differences can still exist between them.

Photo credit: NorthStandard
Published: 3 July, 2026

Hong Kong-based marine fuel supplier Chimbusco Pan Nation (CPN) on Tuesday (16 June) announced that its bunker barge Zhong Ran 23 has become the first vessel in Hong Kong listed on the Marine Department’s official List of Quality Bunker Vessels.

The list under the Quality Bunker Operator Scheme launched on 3 June.

“The Scheme is a voluntary initiative designed to raise the standard of bunkering accuracy, transparency, and service quality in Hong Kong,” CPN said in a social media post.

“To be listed, a bunker vessel must have its Mass Flow Meter (MFM) system independently certified under ISO 22192, the international benchmark for mass flow metering in bunkering operations.”

CPN added it has operated the MFM system across our fleet of fuel oil barges since 2015. 

Manifold Times previously reported Hong Kong’s Marine Department (MD) launching the Quality Bunker Operator Scheme to encourage bunker operators to install and use mass flow meter systems (MFM systems) on their bunker vessels.

MD said the scheme aims to enhance Hong Kong’s bunkering service quality and the competitiveness of Hong Kong ports, thereby further consolidating Hong Kong’s position as an international maritime centre and a major bunkering port.

Under the Scheme, bunker operators of traditional maritime fuel and biodiesel that install and use MFM systems on their bunker vessels, with the MFM systems inspected and certified by an accredited body in accordance with the International Organization for Standardization’s ISO 22192 Standard or equivalent requirements, can apply to the MD for inclusion in the scheme’s “List of Quality Bunker Vessels”, provided they meet the relevant technical and operational requirements. 

Related: Hong Kong backs MFM adoption with voluntary scheme to boost bunkering competitiveness

Photo credit: Chimbusco Pan Nation
Published: 17 June, 2026

Hong Kong’s Marine Department (MD) on Wednesday (3 June) launched the Quality Bunker Operator Scheme to encourage bunker operators to install and use mass flow meter systems (MFM systems) on their bunker vessels.

MD said the scheme aims to enhance Hong Kong’s bunkering service quality and the competitiveness of Hong Kong ports, thereby further consolidating Hong Kong’s position as an international maritime centre and a major bunkering port.

Under the Scheme, bunker operators of traditional maritime fuel and biodiesel that install and use MFM systems on their bunker vessels, with the MFM systems inspected and certified by an accredited body in accordance with the International Organization for Standardization’s ISO 22192 Standard or equivalent requirements, can apply to the MD for inclusion in the scheme’s “List of Quality Bunker Vessels”, provided they meet the relevant technical and operational requirements. 

Details of the bunker vessels successfully included in the List will be published on a dedicated page on the MD’s website for reference by shipping companies and relevant stakeholders.

Participation in the Scheme is voluntary. In addition to receiving recognition from the MD, participating bunker operators will benefit from enhanced corporate image and competitiveness through the adoption of MFM systems, thereby boosting customers’ confidence and helping to create new business opportunities.

 A spokesman for the MD, said: “As an international maritime centre supported by our country, Hong Kong has a strategic location adjacent to major international fairways. Coupled with years of development in marine fuel bunkering, Hong Kong possesses rich experience and talent in the field. For many years, Hong Kong has consistently ranked as the seventh-largest bunkering port globally, the second-largest in our country, and the largest in the Greater Bay Area, providing reliable and competitive fuel bunkering services to ocean-going vessels from around the world. 

“As the international shipping industry has an increasing demand for accuracy and transparency in bunkering services, service quality and measurement precision in bunkering operations have become important indicators of a bunkering port’s competitiveness. The Scheme will enhance bunkering accuracy and transparency, further enhancing the quality of Hong Kong’s bunkering services.

The spokesman added that comprehensive port services are one of Hong Kong’s key advantages as an international maritime centre.

“We will also mandate the use of MFM systems on all methanol bunker vessels this year to ensure that Hong Kong continues to provide high-quality bunkering services in the era of green maritime fuels.” 

Note: The application form for the Scheme can be found on the MD’s website. Interested bunker operators can download the application form from the website or contact the MD’s Green Maritime Fuel Team via email ([email protected]) for details.

Photo credit: Manifold Times
Published: 4 June, 2026