*.Index of List (Tank Cleaning).* • Thank Cleaning Equipment & Maintenance • Tank cleaning pump • Tank cleaning pump & line • Tank cleaning pump • Tank cleaning pump • Factors to be considered for thank cleaning • Property of Cargo • Surrounding cargo tank • Type of coating • Kids & quantity of detergent
Structure of cargo tank • MARPOL regulation • Capacity of by BW heater • Number of tank cleaning machine to be used during tank cleaning • Next cargo • Manpower • Step (Drop) of machine • Kind of tank cleaning water • Temperature of tank cleaning water • Reference table
Preparation for tank cleaning • Tank cleaning • Explain of tank cleaning plan & post at CCR • Preparation • Pre-wash • Pre-cleaning • BW cleaning • Detergent & rinsing • Kinds of detergent and solvent • Methods of detergent T/C • Concentration of detergent & the temperature • Precautions
Fresh water flushing • Steaming (Live, Methanol, Toluene) • Spray (Methanol, Toluene) • Special tank cleaning (PFA, LUB ADD) • Ventilation & Gas free • Mopping • Prevention of sweet • Tank inspection • WWT
Test of heating coil • Cargo record book • Oil record book • Tank coating
*.APPENDIX.* • Heating coil test blow • Cargo record book guidance • Tank cleaning hose test
TANK CLEANING • General : • Cleaning of cargo tank is one of the most important and complex task to operate vessel in an effective & safe way at sea. • There fore, we have to know the correct tank cleaning procedure in order to avoid over- preparation, under-preparation or wrong- preparation and achieve ultimate economical effects.
1. Tank Cleaning Equipment & Maintenance: 1). Tank Cleaning Pump & Line - One is electric motor driven pump which can not adjust pressure of pump and so has to be controlled by means of By-pass designed or by opening tank cleaning line on deck. - The other type is hydraulic motor driven pump which can control pressure of pump by control knob.
2). Tank Cleaning Machine : 1). Grease Type 2). Non-Grease
4). Tank cleaning Heater - it has to be maintained well and to conduct cleaning of the heater by cleaner every 6 months so as to get good temperature during tank cleaning.
2. Factors to be cosidered for tank cleaning: • Property of cargo a. Aggressive cargo (MEK, Methanol). b. Viscosity of cargo (Lubadd). c. Solidity of cargo (Fatty Alcohol, Palm OIL. d. Corrosive (Acetic Acid, Caustic Soda). e. Vapor pressure (Methanol, Acetone). f. Static electricity (Benzene).
g. Solubility in water (MEG, IPA, Acetone, Methanol). h. Dry oil (fish oil, Safflower oil, Soya bean oil etc..,). i. Reaction (SM, MMA). j. Smell (2-EH,DINP, Octanol). 2) Surrounding cargo tanks. When making a T/C plan, surrounding cargo tanks should be taken into consideration.
Kids & Quantity of detergent. According to the type of coating, Use of detergent or Solvent is limited as follows:
Structure of cargo tank • MARPOL regulation • Capacity of butter worth heater • Numbers of tank cleaning machine to be used during tank cleaning • Next cargo • Manpower • Step (drop) of machine • Kind of tank cleaning water
Temperature of tank cleaning water 14) Reference Table
3. Preparation for tank Cleaning 1). Tank cleaning plan to be provided accordingly 2). Explain the plan to crew & the plan to be posted at CCR with signature of crew 3). Following to be prepared in advance
4. Pre wash Following precautions are required : 1). Close all scuppers on deck in order to avoid oil spill 2). Valves on Manifold air cocks, drain line at pump stack to be closed with flange 3). Tank cleaning hose to be connected to OCTOPUS without any leakage 4). All Jumping hose Relating to concerned cargo tank in tank cleaning to be closed 5). Butterworth manholes in pre-wash to be secured not to splash or leak from the holes during pre- wash 6). Watch crew should station on the spot (near cargo pump and Butterworth manholes)
5. Pre-Cleaning 6. BW cleaning (main tank cleaning) 7. Detergent & Rinsing 1) Kinds of detergent and solvent 2) Methods of detergent T/C 3) Concentration of detergent & the temperature 4) Precautions
8. Fresh water flushing 9. Steaming (Live, Methanol, Steming) 10. Spray (Methanol, Toluene) a) Kids of spray b) Safety equipment for spray c) Precautions
11. Special Tank cleaning (PFA, LUBADD) a). PFA (refer to tank cleaning guide in our manual) b). LUBADD 12. Ventilation & Gas free 13. Mopping
14. Prevention of sweat General : Air contains a certain amount of moisture (vapor of water) depending on its temperature and surroundings. This is the reason why dew is generated on a cold surface within a cargo tank containing air of higher relative humidity. The cold surface can be a bulkhead between adjacent cargo tanks containing cold temperature of cargo, a shell plate of which the other side is immersed in the sea, etc..,
1.) Measures in case of occurrence of sweat 2.) Prevention of occurrence of sweat - For your reference, cargoes which loaded as cold temperature are as follows :
15. Tank inspection 1). Following points should be conformed and inspected 2). Problems which have been pointed out by cargo surveyors 3). Causes of tank Inspection failure 4). Preventive Measures
16. WWT 1). PREPARATION 2). Wall Wash by Methanol and Sampling 3). Sample Analysis • Hydrocarbon Test • Chloride • Permanganate Time Test (P.T.T) • Alpha Color Test • Non-Volatile Matters (NVM Test)
4). Figures for Testing HC/CL/PTT/Color Test a) Hydrocarbon Test b) Chloride Test c) Permanganate Time Test d) Alpha Color Test e) Non Volatile Matters Test (NVM) 5). Specification for Wall Wash Analysis 6). Removal of Hydrocarbon 7). Removal of Chloride 8). Removal of Oxide Residue (PTT) 9). Removal of Color
*Sample Analysis* (Standard Solutions for each ppm)
4. Figures for Testing HC/CL/Color Test a) Hydrocarbon Test b) Chloride Test Pure Water Pure Water • 10 ppm CL • 2% Agn O3 • 20% HNO3 • Sample Methanol Sample Methanol (Standard) Zero ppm (Standard) 2 ppm (Sample) (Sample)
C Permanganate Time Test d. Alpha Color Test Methanol KMnO4 • Sample Methanol Sample Methanol (Sample) (Standard (Sample) (Standard)
e) Non Volatile Matters Test (NVM) Residue -’-’-’-’-’-’-’-’- Shale Sample (Start) (Finish)