What this product reference covers.
Bunker fuel describes fuel supplied to a vessel rather than one single grade. It can be distillate, residual, low-sulfur, high-sulfur, bio-containing or another contractually defined marine fuel.
Products within the family.
Names used in commerce can overlap. Use the nominated standard and exact grade rather than relying on a generic product label.
VLSFO
Very-low-sulfur fuel oil supplied to meet an agreed sulfur basis; composition and compatibility can vary between stems.
HSFO
High-sulfur residual fuel used where permitted and where the vessel’s emissions-control arrangement supports it.
MGO / MDO
Marine gas oil or marine diesel oil distillate products commonly selected for lower-viscosity operation.
Bio-bunker blends
Marine fuel containing a renewable component under an explicit grade, blend and sustainability framework.
What the product is built from.
| Component | Technical role |
|---|---|
| Residual refinery streams | Provide heavier energy-bearing fractions and drive viscosity, density, sulfur and contaminant behaviour. |
| Distillate cutter stocks | Adjust viscosity and handling characteristics. |
| Low-sulfur blend components | Support sulfur compliance while making compatibility control especially important. |
| FAME / renewable components | Contribute renewable content where permitted, with separate stability and water-management considerations. |
Define the decision before selecting the panel.
- 01
Confirm that the delivered stem matches the bunker delivery note, contract and nominated grade.
- 02
Establish evidence for quantity/quality disputes using controlled representative sampling.
- 03
Screen before transfer or commingling where instability could threaten fuel availability.
- 04
Set purification, heating and filtration expectations for the received fuel.
- 05
Protect traceability from manifold sample through tank, treatment and engine inlet.
What each result contributes.
“High” and “low” are directional investigation prompts, not pass/fail decisions. Corroborate them using the correct specification, baseline and companion evidence.
| Test / parameter | Typical methods | Why it matters | Possible causes when high | Possible causes when low |
|---|---|---|---|---|
| Sulfur | ISO 8754 / ISO 14596 | Confirms the sulfur basis used for regulatory and contractual decisions. | Wrong stem, tank contamination or poor segregation. | Lower-sulfur blend or different nominated grade. |
| Viscosity | ISO 3104 | Guides transfer, storage heating and injection-temperature management. | Heavier blend, low test temperature or off-grade supply. | Excess cutter stock, distillate mixing or wrong grade. |
| Density | ISO 12185 | Supports quantity conversion, identity and separator configuration. | Heavy residual fraction or contamination. | Higher distillate/paraffinic content. |
| Potential total sediment | ISO 10307-2 | Screens reserve stability under accelerated conditions. | Unstable asphaltenes, incompatible components or ageing. | Stable test response; it does not guarantee compatibility with another fuel. |
| Compatibility spot / reserve-stability evaluation | Recognised laboratory or onboard screening method | Supports a commingling decision between two fuels. | Strong deposit response can reflect asphaltene precipitation from incompatible blending. | Lower response suggests compatibility under the test conditions only. |
| Water | ISO 3733 | Identifies delivered water and supports treatment planning. | Transfer contamination, tank water, seawater or poor handling. | Dry stem or non-representative sample. |
| Aluminium + silicon | IP 501 / IP 470 | Assesses catalyst-fine exposure and purification demand. | Refinery carryover, contamination or insufficient treatment. | Cleaner supply or effective purification. |
| Used lubricating oil markers | ISO 8217-associated screening | Screens prohibited or undesirable waste-oil contamination patterns. | Cross-contamination or inappropriate blending material. | No detectable marker pattern under the method. |
Condition-monitoring application.
Once the product is in service, the question changes from “does it meet a product requirement?” to “what has changed, why, how confident are we and what action is proportionate?”
- 01Preserve chain of custody for representative manifold and retained samples.
- 02Record tank lineage and calculate commingling proportions before transfer.
- 03Trend differential pressure, separator discharge and engine-inlet cleanliness after bunkering.
- 04Link abnormal engine wear to delivered-fuel evidence without assuming causation from a single sample.