What temperature does heavy oil such as No. 6 fuel-oil need to be raised to before combustion?

Heavy oils, such as No. 6 fuel oil, require a specific temperature before they can combust effectively in a burner system. The primary reason for this is viscosity; No. 6 fuel oil has a high viscosity at lower temperatures, making it difficult to atomize and mix properly with air for combustion.

Raising the temperature to around 180°F allows the oil to become less viscous, facilitating proper atomization and enabling a more efficient combustion process. This is crucial in oil burner operations, where consistent and complete combustion is needed to optimize efficiency and reduce harmful emissions.

While other temperatures may be cited, 180°F is the standard threshold identified for No. 6 fuel oil to ensure reliable ignition and effective performance in combustion systems.