To verify the result of the tankcleaning operation the tank and all other equipment that was in contact with the cargo must be inspected. This can only be performed by entering the tank. All standards and procedures related to tank entry must be followed strictly.
In the tank the following items should be inspected, because they are known potential problem areas. Entire tank surface for visible residues. Wall should also be touched and checked for perceptible residues Shadow Areas of the cleaning machine Underneath heating coils Heating coil supports Pump suction well Loading line outlet Tank internals (ladder, cleaning machine, thermowells, Level indicators etc) Furthermore the entire stainless steel tank surface should be inspected for discoloration and pitting. If the tank is coated the coating condition must be checked. The entire tank should also be checked for Smell and Wetness/ Moisture.
Although the inspection of lines is almost impossible, as a minimum test the opening of manifold blind flanges should be carried out, to check lines as much as possible visually for residues and moisture. Also smell in the lines could indicate insufficient cleaning. The pump cofferdam should be purged to detect any possible contamination or seal leak. If required by the loader a Wall Wash must be carried out and checked for compliance with the requirements, which are usually defined by the loader. A variety of analytical procedures are available for testing the wall wash sample.