Viscosity measurement in the petrochemical industry

Todays seagoing vessels often use IFO as fuel. IFO is a blend of cheap heavy fuel oil (HFO) and expensive diesel oil. The fuel is classified using the grades IFO 180, 380 or 580 with higher numbers signifying higher viscosities. At 15°C, IFO has a consistency similar to that of bitumen and is barely pumpable so it must be heated to approx. 50 to 60°C. The required viscosity is determined by the technical conditions on the ship (storage and preheating temperature, injection nozzle viscosity, and maximum pump viscosity). IFO 380 has a viscosity of 380 cSt @ 50°C. The diesel oil is admixed directly in the heavy oil pipeline where there is a static mixer. This pipeline leads to the bunker bridge or directly to the ship. According to MARPOL regulations, a representative sample of each fuel delivery must be taken throughout the bunkering process. The ViscoScope® viscometer measures the viscosity of the bunker fuel continuously during bunkering to ensure the correct amount of diesel oil is added. Furthermore, it documents changes in viscosity throughout the process to a level far in excess of the requirements of MARPOL regulations.