Which grade of oil is commonly used for a boiler system?

The use of Grade 6 oil, often referred to as fuel oil, is prevalent in boiler systems, particularly in high-pressure applications. This type of oil is known for its suitable viscosity, combustion properties, and efficiency in generating heat. It has a higher energy content compared to lighter grades, which makes it beneficial for heating applications in industrial and commercial settings where consistent and high-temperature steam production is vital.

Grade 6 oil, being a heavy oil, is also preferred because it can be burned more efficiently in large industrial burners specifically designed for this type of fuel. Furthermore, its characteristics allow for smooth operation at the high pressures and temperatures typical in boiler systems, minimizing issues related to fuel delivery and combustion stability.

Lighter grades of oil, such as Grade 4 and Grade 5, while usable, may not provide the thermal performance or efficiency required for high-pressure boiler applications. Additionally, Grade 7 oil could be too heavy and not suitable for combustion in standard boiler configurations, as it often requires specialized handling and combustion equipment. Thus, Grade 6 stands out as the most appropriate choice for these systems.