1. The product in this standard is not allowed to go down to next grade automatically when it has not met only one quality figure except it can satisfy all the quality criteria for the next-lower grade. However, the modification for individual figure under special operation condition can be done after being agreed by buyer, seller and producer.
2. Testing method can be the corresponding ones listed in chapter 3. The method listed in the table is for arbitration.
1)The value in the table should not be exceeded by the total amount of the water content measured via distillation as per GB/T 260 plus the deposit measured via extraction as per GB/T 6531. For #6 fuel oil, the deposit via extraction should not be more than 0.5%(m/m); when water and deposit are over 1% (V/V), it should be deducted from the total amount. For #7 fuel oil, the water and deposit shall be deducted from the total amount, if they exceed 2% (V/V). The result based on GB/T 6533 shall govern when there are any discrepancies.
2) In case of the need of low sulphur fuel oil, low viscosity fuel oil can be supplied based on agreement between supplier and purchaser.
3). This limit is set for guarantee of min. heat value, and also for prevent from misuse and misunderstanding of #2 fuel oil.
4). Pour point could be regulated lower or higher based on the requirement of storage and use; however, the viscosity of #2 fuel oil shall not be less than 1.mm2/s when pour point is set below-18℃, while the 90% distilling-off temperature is not under control.
5). if low sulphur fuel oil is needed, #6 fuel oil shall be graded as one with low pour point(not higher than +15℃) or another with high pour point (no max. value to be controlled); it is advisable to use low pour point fuel oil if oil tank and piping are not equipped with heating devices.