Passivation of Cargo Tanks- by Bikramjit S panesar (BSP)

Find here the simplest method of passivation

1.Minimum Required Nitric acid 70% or more with Stainless steel

   Compatibility 200ltr drums                                      – 12 nos ( 100 ltrs only on Board )

2.Fresh water Required for Passivation and tank cleaning – 400 ts

3.Total Passivation time will be 24 hours minimum for all tanks.

4.Initial fill up two tanks sufficient water for Recirculation and Nitric acid about

   2 drums till we get the density of 1.489(approx) ,Recirculate for 2cycles of 45degs

   Pitch for 80mins and transfer into next set of tanks.

5.The same solution can be used in all tanks provided the density remains same,otherwise

    Add water and Nitric acid to get the density.

6.For Recirculation of this solution ,we require chemical hose not available on board for

   Connecting from line to machines.

7.After passivation tanks should be rinsed with Fresh water till we attain PH value 7 at manifold.