Tuesday, June 8, 2010

RAY ALLEN AND OCD -- CAPT AJIT VADAKAYIL


Ray Allen hit a record 8 three pointers in the 2nd NBA finals for Boston Celtics against Los Angeles lakers, yesterday.

He is the most accurate 2 pointer  shooter of NBA too.

He suffers from Obsessive Compulsive Disorder.

When you suffer from  psycho neurotic disorder (OCD) you develop anxiety , become nervous and develop strange repetitive habits.

Michael Jackson did more than 30 plastic surgeries.

To be a excellent shooter in basketball you have to be IN THE ZONE.

It is about the mysterious K force which makes you left and right brain lobe work in harmony-- when action and awareness is in perfect sync--  and body and mind works in unison..

It is possible that in the next match Ray Allen is NOT in the zone -- - and hence misses all his shots.

A list of super achievers who had OCD ( a penalty you have to pay for the divine assistance ) are below--

Beethoven
Einstein
Nikola Tesla
Michael Angelo
Charles Dickens
Darwin.

MDI -- DIPHENYLMETHANE DIISOCYANATE -- BHOPAL KILLER GAS -- CAPT AJIT VADAKAYIL


I have carried this chemical in huge quantities on Chemical tanker ships. 

UNION CARBIDE CORPORATION KILLED 25000 PEOPLE IN BHOPAL WITH MDI--- and maimed three hundred thousand human beings. 

After 26 years , dead souls got a pittance of 500 USD as compensation -- This is American "Agent Orange Justice" for you.  ( The Indian IPL cricket league is worth  4 billion USD ) 




Imagine if the 25000 dead were white skinned , instead of brown. 


Imagine the outcry and candle light vigils -- if the 3 00 000 maimed were seagulls or dolphins or right whales. 

What a disgrace!  

Read on to know more about the killer gas.

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TDI/ MDI / PAPI

TDI /MDI/ PAPI  are extremely poisonous as the name Cyanate suggests ---so take no chances,wear the correct safety equipment and do not try to rush the operation of this cargo at any stage. And if you don’t clean the tank properly it will leave a plastic layer tough to remove .


TDI ( TOLUENE DI ISOCYANATE)

REACTS VIOLENTLY WITH WATER GIVING OUT HEAT AND CO2, HENCE KEEP ADJACENT SBT EMPTY . 

Used for making flexible Polyurethane foams, Polyurethane coatings etc
Clear colourless to yellow liquid, darkens on exposure to sunlight
Sharp pungent sweet fruity odour
Carcinogen
CHRIS/ TDI
UN nuber/ 2078
FOSFA banned
Stainless steel stow
Flash point/ 132C
AIT/ 146C
Specific gravity liquid/1.21 @ 20C
Vapor density (air=1.0)/  6.0
Vapor pressure @ 25 C/  0.025 mmHg
IMO pollution category/ Y
USCG compatability/ Group 12
AH/ 50C
DH/ 35C
VH/ 30C
BP/ 251C
Visc at 20C/ 3 mPas
MP/ 19.5C
TLV/ 0.005 PPM OSHA
Odour threshold/ 0.4 ppm
Combustible
High surface tension
Highly toxic
Heat with thermal oil or adjacent heat
Must have Cyanide kit on board
Soluble   in organic solvents
Insoluble in water
Sinks in water
Gives NO2 gas when it burns
Reacts violently with acids, alcohols , bases , water, strong oxidisers and amines.
Carcinogen.
Risk of sensititation
Not detected by odour unless the conc reaches 10 to 20 times the exposure standard.
By skin absorption liquid is extremely harmful. Dermatitis occurs.
Exposure to low concentration can cause severe respiratory problems.
Vapour inhalation of low concentration can cause ASTHMA-like symptoms, sudden acute broncho spasm and Pulmonary Odema. Headache, Neurosis with depression and unconsciousness.
Reacts with moisture In air even at levels as low as 100 ppm, rapidly evolving unstable carbonic acid gases at sufficient rate to rupture cargo tank bulkheads. Insoluble polymeric Urea is formed.
Prolonged heating above 45 C may cause polymerisation.
Full protective clothing and self contained breathing apparatus when handling hoses,valves,connections.lank cleaning machines etc.
Fire protection/ Alcohol resistant foram, regular foam, water spary ( not into closes tank ), dry chemical

Although TDI is a hazardous material, the hazard may be minimized if appropriate precautions are observed Typically, there are four routes of potential exposure: inhalation, skin contact, eye contact and ingestion.

Inhalation of TDI vapors may cause irritation of the mucous membranes of the nose, throat or trachea, breathlessness, chest discomfort, difficult breathing and reduced pulmonary function. It is important to avoid exposure above the TLV to minimize the possibility of respiratory sensitization.

Tests have shown that the least detectable odor level of TDI is approximately 0.2-0.4ppm. This odor threshold is significantly higher than the OSHA Permissible Exposure Limit (PEL) of 0.02 ceiling. If an individual can smell TDI, overexposure has most likely occurred. Airborne overexposure, well above the PEL, may result additionally in eye irritation, headache, chemical bronchitis, asthma-like findings, or pulmonary edema. TDI has also been reported to cause hypersensitivity pneumonitis, which is characterized by flu-like symptoms, the onset of which may be delayed.

Control of TDI exposure to the recommended guidelines (0.005 ppm as Time-Weighted Average, 0.020 ppm as Short Term Exposure Limit) is believed to protect against sensitization. However, if an individual has become sensitized to TDI, an asthma-like response may then result from very low exposures to TDI. In the event of skin contact, wash thoroughly with soap and flowing water for at least fifteen minutes (A recent study has indicated that corn oil or polyglycol-based cleaners may remove MDI more effectively than soap and water, and this may also apply to TDI.(5) Cleaning soon after contamination was also important.).

Promptly remove all contaminated clothing (including shoes) while washing. If the skin is burned or irritated, seek medical attention. Decontaminate clothing prior to re-use by soaking the garments in an 8 percent ammonia solution for one hour prior to laundering with hot water and detergent. Destroy all contaminated leather items including shoes, belts, and watchbands.

The  easiest and most convenient way to handle spilt TDI is to react it with polyol to produce a
low-quality foam, which then can be sold or used as a manufactured product. (CAUTION: The TDI/polyol reaction is exothermic, which may cause spontaneous combustion.)

Empty TDI drums can be decontaminated by filling them with water or a decontamination solution (5-10% sodium carbonate) and allowing them to stand unsealed for at least 48 hours. WARNING: Under no circumstances should empty drums be burned or cut open with a gas or electric torch, as toxic decomposition products may be liberated.

The use of suitable respiratory equipment is required whenever there is a potential for exposure to airborne TDI levels in excess of permissible exposure limits (PEL 0.02ppm-ceiling, TLV 0.005ppm - 8hour TWA).

RESISTANCE; ALWAYS CONSULT CARCO HOSE RESISTANCE LIST.

Following hose material is resistant to TDI

Butyl rubber
Polyethylene
Viton rubber
Teflon ( Hostaflon )

Chemicals Needed for Cleaning/Personal Protection

Low moisture content Chlorinated Solvent MEC (Methylene Chloride ) MARPOL   (  Y ) , or Trichloroethylene ( Y) or,  Perchloroethylene (  Y ) approx 8-10 M3 per tank,  charterer will supply. If using Methylene chloride ( Dichloro methane ) you will need 15 cum as its evaporation rate is more. Its BP is 40C and SG is 1.34. Some coatings like Phenoline and Devchem 253 are not resistant to MEC.

Sufficient TOLUENE for TDI line filling, say 200 Ltrs for each hose length x 2  (loading and discharging)

Cyanide kit:
12 pearls Amyl nitrite.
2 ampoules Sodium Nnitrite 10CC 3% solution.
2 ampoules Sodium Thiosulphate 50CC 25% solution.
Crush Amyl Nitrite capsules 5 times at 15 second intervals and hold under nose of a gassed victim.

200 Ltrs Aqua Ammonia
200 Ltrs IPA 30% (Iso propyl alcohol)—to use as solvent if TDI falls on skin.
Two litres of 1% Tincture of Green Soap
In case of spill first neutralize it with 50% Ethyl Alcohol, 40% water and 10% conc Ammonia.   If spill is small mix with sand or Sodium Bicarbonate. Pack it in a cardboard box and burn it in an open pit using paper as fuel.

EXTRA EQUIPMENT NEEDED:

Sufficient extra hoses (not ships normal hoses) and/or SS pipe  enable reach manifold area from pumpstack.

Two SS Spool pieces each with one inch drain valve fitted. ,

Two SS portable valves for the pumpstack.

Prior to Loading:

TDI, Clean tank to water white plus standard

Pressure test heating coils for leaks, then air blow water condensate from coils, followed by nitrogen blowing to ensure moisture free.  Blank off both inlets and returns. The cargo is water reactive and hence ensure NO water comes in contact.

Check/test function of PV Valve

Air blow PV vent line to ensure no water trapped in Line (especially if slight list or trim).

Mop dry cargo pump deepwell.

Pressure test cargo pump cofferdam. Purge out cofferdam with nitrogen and fill completely with DOP             ( Dioctyl Phthalate which has a VD of 13.5). 

Fit pressure gauge to vent line so tank pressure can be monitored during loading, voyage and discharge.

Prepare/connect vapour return system.  Calculate Pressure Drop.

Prepare 200 ltrs of neutraliser in case of spills:
80 ltrs freshwater, 100 ltrs IPA Iso propyl alcohol , 20 ltrs Aqua Ammonia.

Prepare a solution of 99% IPA and 1% Tincture of Green Soap for personal protection.

Loading  TDI or MDI

Cargo tank will be purged with Nitrogen to minus 40 deg C dew point or 0.25% by shore and pressure may be as high as 10 bars, therefore leave tank cleaning hatch and ullage hatch open as well as PV valve to ensure whole system is purged and tank does not have structural damage due to over pressurization.

When nitrogen purging is complete and shut down, secure the tank and put PV valve in normal operating position.

Ensure safety shower in operation.

Draeger tubes must be ready for use around the cargo area. Tape off and cordon the loading area.

When shore ready to start.  Open valves at shore connection and pumpstack.

For TDI you cannot do open ullaging or sampling.

         On Completion Loading

Shore will blow line with nitrogen to tank.
Close all valves and disconnect shore hose and vapour return.
Samples must be taken with closed sampling device.
Fill ships hoses with Toluene using Graco pump. Leave the Toluene inside for 3 days.
Wash hoses with warm water 50-60 C and steamed out and drained. 

Voyage

Heat as per charterers instructions by Adjacent Heated Cargo ONLY, unless ship has thermal oil heating,( TDI Normally 35 C ). Do not allow the temp to go below 21C or >45C
Do NOT have any cold ballast in the double skin.
Maintain nitrogen blanket at positive pressure, minimum 50 mb.

Discharging

Use vapor return hose . DO NOT DISCHARGE without vapour return hose.
Inert with N2 while discharging.

Cargo hoses to be blown with shore nitrogen at end of dischg. Fill Chlorinated solvent via manifold from storage cargo tank.

Pre-Cleaning

Chlorinated solvent 8-10 M3 of moisture spec <400ppm should already have been loaded into clean extra-dry tank and heated to 30-35 C for TDI ). The chlorinated solvent has to be heated to >MP of the Isocyanate, but

Prepare 2 SS tank cleaning machines and TDI resistant cleaning hoses.

Release ullage hatch but do not lift open, open PV valve. (in case of rapid pressure increase when solvent added.)

Transfer this solvent to cargo tank via manifold and through cargo hoses with pumpstack valve closed initially to ensure line is totally filled, then opened fully until all solvent transferred into tank.

Disconnect cargo hose from pump stack and connect blind flange with Y for tank  cleaning hose to fit.

Place machines in tank and cover opening to stop any liquid splashing out.

Commence circulation full strength for minimum two hours. Shore to supply Nitrogen continuously during circulation. At this time reconnect shore line (or shore slop line) to ships line ready for use.

After circulation, disconnect blind with Y and reconnect ships hose to pumpstack, and pump out to shore the Solvent TDI slop. After stripping blow line again with nitrogen, Stop shore nitrogen to tank and batten down tank until at sea.

When shore hose finally disconnected, fill ships hose/line again with chlorinated solvent as previously done.

NOTE: IF SHORE IS UNABLE TO ACCEPT THESE CATEGORY  Y  SLOPS AND THESE ARE BEING TAKEN TO ANOTHER PORT FOR DISPOSAL, REMOVE TANK CLEANING MACHINES AND BATTEN DOWN TANK TO AVOID MOISTURE ENTERING. 

SLOP SHOULD NOT BE CARRIED FOR LONG PERIODS AS POLYMERISATION CAN OCCUR.

Cleaning at Sea

After the solvent wash—wash the tank with water and detergent as if the solvent was the last cargo. .Make the entries in the Cargo record book.

Blow out cargo hoses, rig tank cleaning machines.

Blow out DOP from pump cofferdam (overboard) and flush with MEC then blow dry with nitrogen.
          
If some Methylene chloride is left in the sump put some Methanol into the tank and keep heating coils crack open.

First give a cycle cold sea water wash, but above the MP of TDI which is 19.5 deg C.

Then Hot wash tank for 2 hours with sea water.
Give FW rinse .
Steam tank for 2 hours, then mechanically ventilate for 3 hours.

Test tank with Draeger tube before entering to inspect.
TDI is a bad previous cargo for PTT and UV test.

There may be some tough brownish film residue or URETHANE layer ( moisture effect ) which is difficult to remove. Scour with 3m Scotch brite abrasive pads.  You may find polymerised bubbles with liquid cargo underneath and will need to neutralise.

TDI and MDI are extremely poisonous so take no chances, wear the correct safety equipment and do not try to rush the operation of this cargo at any stage.

If Gasoil is used for cleaning ( for TDO only ) , make sure the moisture is <400 ppm at 10 Cum per tank.. Recirc Gasoil for 2 hrs. Toluene can be used for line cleaning.  4 parts of Gasoil are required to dissolve 1 part of TDI.

Loading Arrangement

MANY LENGTHS OF CARGO HOSES WITH PORTABLE VALVE TO BE RIGGED FROM PUMPSTACK HOLE TO SHORE MANIFOLD .  DO NOT LOAD THROUGH FIXED SHIPS CARGO LINES . OTHERWISE POLYMERISATION / PLASTIC IN LINES WILL OCCUR.
 

Additional equipment required:

2 x portable valves
1 x blind pumpstack valve
2 x SS spool piece with drain valve 1 inch for blowing line and filling hoses with chlorinated solvent after load.
SUFFICIENT NUMBERS HOSES TO REACH CLOSE TO MANIFOLD AREA.


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MDI (DIPHENYLMETHANE DIISOCYANATE)

Characteristics  MDI

Used for making rigid foam.
CHRIS/ DPM
Dark coloured liquid with faint tarry odour.
MP (pure)/ 37.2 deg C
Specific gravity (liquid)/ 1.197 @ 70 deg C,
BP/ 196C
Coefficient of expansion/0.00098 per degree C
Vapor density (air= 1.0)/8.5
Vapor pressure @ 46 C/very low---0.00009 mm HG @25C
IMO pollution category/ Y
USCG Compatability/Group 12
UN number/2489
AH/ 60C
DH/ 45
VH/ 39C
TLV/ 0.05 ppm
FP/ 218C
MDI is not water soluble. Sinks in water
Viscosity 12 mPas at 40C
FOSFA banned

Incompatible with strong oxidizing agents.

Reacts violently with acids, alcohols and strong acids.

If inhibited by Ammonia do not stow in zinc tank ( pH >9 ).

Solubility, - soluble in Acetone and Kerosene

Flammable at high temperatures. Fire will cause polymerization and dangerously high pressures.

Reacts slowly with water producing C02,(Carbon dioxide),

Vapor is strong irritant to eyes and throat causing eye and lung injury, even low concentrations cannot be tolerated. On heating MDI gives toxic vapors of Carbon Monoxide, oxides of Nitrogen and Hydro Cyanide gas with very high VP.

REACTIVITY: MDI is unstable in traces of moisture, slowly forming C02 gas (carbon dioxide)

SAFETY: Full protective clothing and self contained breathing apparatus when handling hoses,valves,connections,tank cleaning machines.

Heat as per charterers instructions by Adjacent Heated Cargo ONLY, unless ship has thermal oil heating,

Fill ships hoses with chlorinated solvent like Perchloroethylene or Methylene chloride for MDI,
say 200 Ltrs for each hose length x 2  (loading and discharging)

At normal unloading and storage temperatures, MDI has a relatively low vapor pressure. With adequate ventilation, airborne MDI vapor concentrations are unlikely to reach or exceed exposure guidelines.

Nevertheless, at elevated temperature, or if MDI is aerosolized by compressed airblow , health problems will result.

Inhalation of MDI may cause irritation of the mucous membranes of the nose, throat or trachea,
breathlessness, chest discomfort, difficult breathing and reduced pulmonary function. It is important to avoid exposure above the TLV to minimize the possibility of respiratory sensitization.

Overexposure well above the PEL may result in eye irritation, headache, chemical bronchitis, asthma-like symptoms or pulmonary edema. Diisocyanates have also been reported to cause hypersensitivity
pneumonitis, which is characterized by flu-like symptoms, the onset of which may be delayed. Skin contact may result in an irritant or allergic contact dermatitis and may play a role in respiratory sensitization.

Skin staining or discoloration may occur. Long term contact may cause redness, swelling and blistering. Control of MDI exposure to the recommended guidelines (0.005 ppm as Time Weighted Average, 0.020 ppm as Ceiling) is believed to protect against sensitization. However, if an individual has become sensitized to MDI, an asthma-like response may then result from very low exposures.
The ACGIH TLV for MDI is 0.005 ppm (0.05 mg/m3) as an 8-hour Time Weighted Average (TWA). OSHA requires that exposures be controlled to below a PEL of 0.02 ppm (0.2 mg/m3) as a ceiling, to prevent lung tumours.

In the event of skin contact, wash thoroughly with soap and flowing water ( corn oil or polyglycol-based cleaners may remove MDI more effectively than soap and water. Decontaminate clothing prior to re-use by soaking the garments in an 8 percent ammonia solution for one hour prior to laundering with hot water and detergent.

When transferring MDI, personal protective equipment should be worn by crew engaged in cargo work, tankcleaning
This may, depending upon conditions, consist of:
• Chemical goggles;
• Face shield;
• Chemical gloves, resistant to MDI
• Long-sleeve coveralls or full body suit, resistant to MDI
• Fitted boots made of material  resistant to MDI, and;
• Head protection, such as a close fitting hood, made of a material resistant to MDI.


PAPI ( POLYETHYLENE POLYPHENYL ISOCYANATE )

UN number/ 2206(i) 2207
MARPOL category / Y
Maintain temperature between 24C and 40C. Do not allow the temperature to go below 18C r> 32C
CAS / 9016-87-9 0.1-0.5   
OSHA-PEL /  TWA- Ceil- 0.020      
ACGIH-TLV /  TWA- 0.005 ppm STEL

CAPT AJIT VADAKAYIL ( 28 years in command )-- POSTED IN PUBLIC INTEREST.
..

Sunday, June 6, 2010

STEAM HEATING ON CHEMICAL TANKERS-- CAPT AJIT VADAKAYIL




ALL CHEMICALS CARRIED AT SEA ARE HEATED BY HOT WATER AND NOT STEAM.   THE TANK HEATING COILS AT EXIT POINT OF TANK , MUST CONTAIN HOT WATER NOT STEAM.   

THE TEMPERATURE OF WATER IN THE COILS IS ADJUSTED BY THE RETURN VALVE FROM TANK .   THE STEAM INLET VALVE TO TANK MUST BE 100% OPEN ALWAYS .


Heating is done to ----

Reduce viscosity. Viscosity is measured in centistokes. Water is one cst. As the temp rises viscosity reduces at the rate of 2% per degree.

Reduce pour point. Pour point is 3 degrees over temperature were liquid coagulates.

Reduce cloud point. Cloudpoint is the temp where cystallised solids forms inside liquid and settles on bulkheads.

Avoid crystallization. Some cargoes like Caustic Soda require heating to avoid crystallisation.

Avoid freezing of cargo. Some cargoes like Cyclohexane require heat to avoid freezing.

To avoid pre-wash at discharge port. Heating may also be required in order to comply with MARPOL regulation for prewash ( Phenol will have to be prewashed if dischg berth temp is below MP plus 10 deg.

To increase the water solubility.  For example Phenol is soluble in water at a temp of 60 degrees.

To reduce unpumpables at tank sump.

To reduce delivery pressure of the ships centrifugal deepwell pumps.

To avoid claims from the charterers who want a particular voyage and discharge heat. Under heating and over heating will both result in claims from charterers.

To reduce clingage. Clingage does not include the tank bottom

For tank heating coil system the size of the main return line is smaller than that of the steam inlet line. Because the return line is supposed to contain water only, while the main inlet line is supposed to contain steam only. For the steam winches the case is opposite, the return line is bigger as it contains expanded steam.

From the engine room boiler steam arrives on deck through the main inlet steam pipe. Before it enters the deck it has to pass through a PCV or pressure control valve of 1 bar to 7 bar range. There will be a small bypass line around this valve for initial warming prior starting. This bypass must be operated for at least 45 minutes on a small chemical tanker, before the PCV is opened. Heating must be started slowly to reduce thermal stresses.

When not in use the steam coils should be full of fresh water---unless the cargo is water reactive in which case it must be blown dry and blanked.

For initial starting the PCV is put at 1 kg and then slowly increased. Open all drain cocks in the steam inlet line till water is ejected and steam comes out.

Only water should return to engine room through the return line –otherwise it is a huge waste of money. This is one of the energy conservation items . This water must be pure and should not contain any cargo. There is an inspection chamber ( called siphoning drum ) where the first one hour of return water must be monitored. On a chemical tanker you can view through a glass port to check for floating insoluble cargoes, get the odor from the vent to check for volatile soluble cargoes, and drain from the bottom to check for sediments or high SG insoluble chemicals. 

When carrying heating cargoes the return siphoning drum content must be inspected daily check for any traces of cargo—if any are found then the heating coils must be drained individually to find out the culprit. This coil can then be blanked off. The drain valves and siphoning drum must be checked twice daily for ingress of cargo.

Heating of tank is regulated also by the number of active coils from inlet manifold. Temperature of return line has to be taken regularly to find out if you are over heating or under heating. Centre Tanks with double skin has to be heated less than wing tanks who have a cold interface with ballast.

IT IS IMPORTANT TO KNOW HOW TO STOP HEATING. OR YOU DESTROY THE HEATING SYSTEM.  THE IDEA IS TO AVOID TRAPPING HIGH PRESSURE STEAM WHICH ON COOLING WILL CAUSE A HIGH VACUUM BUILD UP . THIS  WILL CAUSE CORROSIVE / EXPLOSIVE/ TOXIC CHEMICALS TO BE SUCKED INTO THE COILS .  First close the inlet valve . Then open drain cock in front of the return valve. Then close return valve.

One single leaking coil can contaminate other clean coils via the return manifold. Steam blow contents must always be checked for pH

If steam heating coils fail ---in an emergency ,use adjacent heat including live steam in ballast water around the tank. When no heating is done temp usually drops 1-2 deg C a day.

When you heat raise the temp to 5 to 6 deg a day---NOT MORE. Many cargoes perish due to indiscriminate overheating . Too high temp causes unacceptable VP or chemical/ physical change which can be permanent. When veg/ animal oils are overheated Carbon Monoxide  is formed which can affect the sweeping party. Overheating luboils can cause oxidation of cargo and colour off spec. Overheating Molasses cause thermal decomposition and total destruction.

Make sure cargo is at the discharge heat four days prior arrival. To expedite the process, remove cold ballast interface.

The heating coils of tanks not required to be heated must be blanked on both entrance and exit and log entry made. In order to avoid confusion, heating coils  should only be used when a cargo requires heating. Any other cargoes on board should have their coils blanked on both the inlet and return side. This is also of paramount importance if the cargo is inhibited, subject to polymerisation ( Styrene Monomer ), or has a violent reaction water ( Sulphuric acid ) etc. 

Tanks which require heating must be pressure tested prior loading and log entry made. If the coils leak –you cannot load unless permanent repairs with proper stainless steel welding is done by chief engineer.

If a heated valve is tight allow it to cool. If you force it , you damage it.

Some ships have deck mounted heat exchangers –Framo pump discharges into a heater at about 60 bars.                       
The two methods for testing steam coils on board are:
Hydraulic testing using water
Steam pressure testing

It is possible to carry out pneumatic testing (air), but this method is considered unreliable and will NOT be considered suitable for meeting company standards, and is NOT to be used.

Hydraulic testing of heating coils is time consuming and cannot be carried out in all tanks on a regular basis. The hydraulic testing of heating coils must be carried out, by ship's engineers, once a year. or as dictated by the company. It is recommended that tank tests are staggered so they are not all due at the same time. Hydraulic testing must also be done by chief engineer after any permanent repairs have been made to the heating coils. The results of all hydraulic tests must be recorded in the log book and the planned maintenance system.
Steam testing of coils is to be carried out before the loading of every heated cargo as a policy.

Thermal oil heating coils are to be hydraulic tested, using oil, every two years. If defects occur, then the coils must be tested annually.The coils must also be tested after any repairs.

All coils must be hydraulically tested when they have been replaced following disassembly for coating work. etc. In a docking situation this should be done before leaving the yard. If this is impossible, then testing should be scheduled for as soon as it is practical.

Any cargo damage due to steam coil leak or ingress into steam coils is un acceptable to us, it is considered as personal failure.

For cold hydraulic testing use Graco pump and a 200 litre FW drum to pressurise to 12 kg.  Do not forget to inspect the riser piping. Testing must be done coil by coil. Also check for loose nuts from steam coil clamps.

It is the more severe of the two test methods due to the fact that when using steam, heat expansion can cause small leaks to seal, and also higher pressure (1.5 times) than working pressure can be used.

When carrying out hydraulic testing, it is important that the tank is completely dry , and cold water ballast interface at the tank bottom is removed. This will make the detection of very small leaks much more easier—any water at the bottom means a leak.
Install blanks to provide the required test boundary. Connect the hydraulic test pump to the coils and install a suitable pressure gauge. Fill the coils with good fresh water. Build up the pressure in the coils to 1.5 times their maximum rated working pressure. Close the hydraulic pump valve to prevent pressure drop. Monitor the pressure of at least 30 minutes, without additional pumping. If a leak is indicated by a pressure drop, then the entire system must be checked until the leak is found.

After 30 minutes, the coils are to be thoroughly examined. The thorough examination must include a very close visual inspection and also feeling by hand under the coils in order to detect any pinhole leaks. Such pinhole leaks may not be indicated by a pressure drop on the manometer and can also be very hard to detect by the eye.

Repair and properly document all leaks detected. Repeat the test procedure after repair.

The testing of coils using steam pressure from the ship's boiler:
Misleading results can be obtained from steam testing due to steam condensation in the coils if the test is not properly conducted as described below. The maximum maximum boiler pressure is to be used . The coils to be tested should be exhausted to atmosphere until live steam is issuing from the return. Close the return against the steam. The steam pressure must be held for 30 minutes prior to inspecting.

Another 2 in one ( DUAL )method is with return valve closed, open the steam inlet at 7 kg . This will then give an easy hydraulic test on coil due to trapped condensate in line. Inspect the coil for water leaks. Following the above, return valve to be opened and steam allowed to flow through the coil via the steam trap. After 30 minutes have elapsed, coils to be inspected for leaks. By shining a torch light along the coil, escaping steam will be highlighted.

If a leak is detected and a section of piping has to be repaired, a proper hydraulic test should be carried out after the repair is completed as a policy. Install blanks to provide the required test boundary, ie isolate only the coil to be tested.

When carrying out visual inspections for leaks, look closely for signs of corrosion. Corrosion leaks may require further close examination of the coils to determine the amount of damage. Bad corrosion may mean the whole section may have to be cropped and renewed. All corrosion problems are to be reported to the chemical operator immediately.

Heating coils not in use must be steam pressure tested every 3 months and its results must be recorded. If heating is not to be done the coils must be blanked—and log entry made

If the Master is unable to comply with the charterers heating instructions he must inform the  chemical operator well in advance. Make sure that there is enough bunkers on board to run the boiler.

Under no circumstances should cargo exceeding tank lining resistance tables temperatures be accepted for loading. Be aware of the maximum cargo temperature stipulated in the charter party.

It is the responsibility and duty of chief officer to take the temperature  twice daily—the critical heating log must be signed by him daily without fail—signature must not be postponed to the next day. A signed copy must be hung in CCR bulkhead for Chief engineer to monitor.

The steam valves of wing tanks and forward tanks are usually opened more. The % of the return valve opened must be entered in the log column.

The Chief engineer must log down daily the bunkers used in boiler solely for heating cargo.

Heated cargo temps must be taken at 3 levels inside tanks. As the cargo is discharged , the steam heating into the tank must be reduced. Heated cargoes must be stripped immediately. IT MUST NOT BE POSTPONED.

There must be an action plan ( as part of the pre-load pre-dischg meeting ) to melt solidifying cargoes from inside the pipelines and to prevent valves from getting frozen in place.  If steam hoses have to be used the crew must use PPE and heat resistant gloves.. Steam must be applied at the underside of
the pipes. It is more effective to use hot water on a burlap lagged pipes , especially at bends.

If the pump impeller is frozen steaming into empty DB via sounding pipe can be considered—but inform the chemical operator first.

Before discharging a high MP cargo consider recirculating the cargo before opening the tank delivery valve and the manifold valve.

STEAM TRAPS
Simply put, steam traps are automatic valves that release condensed steam (condensate) from a steam space while preventing the loss of live steam. They also remove air and non-condensables from the steam space.
Once steam has transferred Btus and becomes hot water, it is removed by the trap from the steam side as condensate and either returned to the boiler via condensate return lines. Continuous flow traps will continuously discharge condensate.
Normally there will be no need for level controller of tank cleaning heater if you do not excced 8 machines.

Steam traps on return line coils senses the difference between flow of water and steam. There are filters in front of each steam trap. Clean these filters and also steam traps regularly.

Steam traps must be overhauled regularly to ensure correct function of the steam trap and heating of the cargo. Twice a year and before loading high-heat cargo it is also recommended to open up the steam trap and blow coils through and remove any previous cargo which may have leaked into the coil thereby blocking the trap and narrow parts of coil on deck causing nil heating and subsequent slow discharge claim.


CAPT AJIT VADAKAYIL ( 28 YEARS IN COMMAND )

MARPOL RULES FOR ANNEX 2 CHEMICAL TANKERS-- CAPT AJIT VADAKAYIL

                  

No tank washings containing chemicals can be discharged into the sea unless ---the ship’s speed is 7 knots, depth of water is greater than 25 metres, and distance from land is greater than 12 miles.

In Antartic ( south of 60S Lat )  categories X Y and Z cannot be discharged and it is the only special area after 1.1.07 .

For list of high volatile cargoes which can be vented see P&A manual. If VP > 5000 Pa @20C ( 50mb ) you can the vent the cargo off into the atmosphere.

MARPOL Annex II grades “noxious liquid substances carried in bulk” into 3 categories graded X Y Z, according to the hazard they present to marine resources, human health or amenities.

Every ship constructed on or after 1 January 2007 shall be provided with a pumping and piping arrangement to ensure that each tank certified for the carriage of substances in Category X, Y or Z does not retain a quantity of residue in excess of 75 litres in the tank and its associated piping

Ship details
Stripping requirements (in litres)
Category X
Category Y
Category Z
New Ships: keel laid after 01/01/2007
75
75
75
IBC ships until 01/01/2007
100 +50 tolerance
100 + 50 tolerance
300 + 50 tolerance
BCH ships
300 + 50 tolerance
300 + 50 tolerance
900 + 50 tolerance

Category X:

Noxious Liquid Substances which, if discharged into the sea from tank cleaning or deballasting operations, are deemed to present a major hazard to either marine resources or human health and, therefore, justify the prohibition of the discharge into the marine environment
 Examples are Acetone Cyanohydrin, Carbon Di Sulphide, Nonyl Phenol, Di Butyl Pthalate, Epichlorohydrin, Ethyl Acrylate Monomer, Vinyl Toluene, Butyl Benzyl Pthalate, Alpha Methyl Styrene, Calcium Naphthalate etc. Cumene has been down graded from 1st Jan 2007 from A to Y—however more stringent stripping is required.
You are not allowed to discharge Cat X washings into the sea. A tank from which a substance in Category X has been unloaded, shall be prewashed before the ship leaves the port of unloading.  The resulting residues shall be discharged to a reception facility until the concentration of the substance in the effluent is below 0.1% by weight.  When the required concentration level has been achieved, remaining tank washings shall continue to be discharged to the reception facility until the tank is empty.   See P&A manual for the water quantity and number of cycles.
The Govt Surveyors sign and stamp has to be endorsed on the Cargo record book entry. For prewash one cleaning cycle is defined as two consecutive identical rotations of 360 degrees . Any water subsequently introduced into the tank may be discharged into the sea in accordance with the discharge standards in regulation
When discharging Cat X cargoes superstrip is not mandatory as you are prewashing ashore till the tank is empty.
To find out how much water to use in prewash for 0.1% conc by weight—
Find out how many m3 of water is ejected in one cycle.  At 13 m3 /hr and 7.5 min for one cycle, it is 1.63 m3 ( 13/60 X 7.5 )
1.63 X no of cycles X no of machines ( as per P&A manual )
The residual quantity of pre-wash tank washings in:--
1) Volume of water to use ( CuM )
2) Duration of wash in minutes
is tabled in the P&A manual for each cargo tank .

Both tables will have the value K on the X axis and the ships cargo tanks on the Y axis.
k =          a factor having values as follows:
Category X, non-Solidifying, Low-Viscosity Substance,   k = 1.2
Category X, Solidifying or High-Viscosity Substance,      k = 2.4
Category Y, non-Solidifying, Low-Viscosity Substance    k = 0.5
Category Y, Solidifying or High-Viscosity Substance       k = 1.0

Typical pre-wash volumes in CuM / times  in minutes---------- for a SS tank of 1500 cum with portable machines (15 cum/ hour ) would be:--

Proforma--- K/ Volume in CuM / Duration in Minutes

0.5/ 1.02 / 4.1
1.0/ 2.03 / 8.1
1.2/ 2.44 / 9.8
2.4/ 4.88 / 19.5

A cleaning machine cycle is defined as the period between two consecutive identical orientations of the machine (rotation through 360°).
After washing, the cleaning machine(s) shall be kept operating long enough to flush the pipeline, pump and filter,and discharge to shore reception facilities shall be continues until the tank is empty.
Number of cleaning machine cycles to be used in each location
Category of substance
Number of cleaning machine cycles
Non-Solidifying Substances
Solidifying Substances
Category X
1
2
Category Y
1/2
1


Prewash procedures for non-Solidifying Substances : Tanks shall be washed by means of a rotary water jet, operated at sufficiently high water pressure. In the case of Category X substances cleaning machines shall be operated in such locations that all tank surfaces are washed. In the case of Category Y substances only one location need be used.
Prewash entries in Oil record book –Annex 2:
Identify port---Identify tank(s), substance(s), category(ies) discharged ashore---Have tank(s), pump(s), and piping system(s) been emptied?---Has a prewash in accordance with the ship’s procedures and arrangements manual been carried out?---Have tank washings resulting from the prewash been discharged ashore and is the tank empty?---An exemption has been granted from mandatory prewash---Reasons for exemption----Name and signature of authorized surveyor.----Organization, company, government agency for which surveyor works.

Category Y

WHENEVER YOU CARRY VEG OILS OF CATEGORY Y-  ASK FOR THE VISCOCITY IN mPa.S AT 20 DEG C AND MP --IN THE SHIPPING DOCUMENT OR B/LADING.    IT DOES NOT MATTER IF THE VEG OIL IS DRYING OR SEMI DRYING.
Noxious Liquid Substances which, if discharged into the sea from tank cleaning or deballasting operations, are deemed to present a hazard to either marine resources or human health or cause harm to amenities or other legitimate uses of the sea and therefore justify a limitation on the quality and quantity of the discharge into the marine environment;
Examples are Acrylonitrile, Biodiesels, Carbon Tetrachloride, Caustic coda , Ethylene di Chloride , MDI, Lub Additives, Phenol, Sulphuric acid, Benzene, Toluene, Xylene, Ethylene Glycol , Methanol, Lard, Palm Oils, All VEG OILS and FATS, Hexane, Vinyl acetate   etc.
For High-Viscosity or Solidifying Substances in Category Y the following shall apply ( note –the values are given in the cargo list of P&A manual ) :

1              a prewash procedure shall be applied;
2              the residue/water mixture generated during the prewash shall be discharged to a reception
                facility until the tank is empty; and
.3            any water subsequently introduced into the tank may be discharged into the sea
High-Viscosity Substance means a noxious liquid substance in Category X or Y with a viscosity equal to or greater than 50 mPa.s at the unloading temperature.
Solidifying Substances and substances with viscosity equal to or greater than 50 mPa.s at 20°C shall be washed with hot water (temperature at least 60°C) when water is used as the washing medium, unless the properties of such substances make the washing less effective.

Only solidifying and viscous Category Y cargoes need to be prewashed ashore (with >60 deg C water) prior departure discharge port.
Solidifying means –---if MP > 15C and dischg temp of cargo is within 10 deg C /  if MP < 15C and dischg temp of cargo is within 5 deg C.
Prewash procedures for Solidifying Substances
1 Tanks shall be washed as soon as possible after unloading. If possible tanks shall be heated prior to washing.
2 Residues in hatches and manholes shall preferably be removed prior to the prewash.
3 Tanks shall be washed by means of a rotary water jet operated at sufficiently high water pressure and in locations to ensure that all tank surfaces are washed.
4 During washing the amount of water in the tank shall be minimized by pumping out slops continuously and promoting flow to the suction point (positive list and trim). If this condition cannot be met, the washing procedure shall be repeated three times with thorough stripping of the tank between washings.
5 Tanks shall be washed with hot water (temperature at least 60°C) unless the properties of such substances make the washing less effective.
6 The number of cycles of the cleaning machine used shall not be less than that specified in table 6-1. A cleaning machine cycle is defined as the period between two consecutive identical orientations of the machine (rotation through 360°).
7 After washing, the cleaning machine(s) shall be kept operating long enough to flush the pipeline, pump and filter,and discharge to shore reception facilities shall be continues until the tank is empty.
Table 6-1 -- Number of cleaning machine cycles to be used in each location
Category of substance
Number of cleaning machine cycles
Non-Solidifying Substances
Solidifying Substances
Category X
1
2
Category Y
1/2
1

Those substances which have a viscosity equal to or greater than 50 mPa.s at 20°C shall be washed with hot water (temperature at least 60°C), unless the properties of such substances make the washing less effective.

Prewash procedures for non-Solidifying Substances : Tanks shall be washed by means of a rotary water jet, operated at sufficiently high water pressure. In the case of Category X substances cleaning machines shall be operated in such locations that all tank surfaces are washed. In the case of Category Y substances only one location need be used.

Recycled medium prewash—Can be adopted for washing more than one tank. The cargo concentration in the water / medium 5% based on stripping test quantities of the P&A manual.

Every ship constructed on or after 1 July 1986 but before 1 January 2007 shall be provided with a pumping and piping arrangement to ensure that each tank certified for the carriage of substances in Category X or Y does not retain a quantity of residue in excess of 100 litres in the tank and its associated piping

The definition of high viscosity in the revised Annex II would mean that a lot of vegetable oils (primarily the soft oils) could be required to be prewashed.
It has been suggested that for certain oils, such as Soyabean oil, the discharge temperature could be raised slightly to bring the product out of the high viscosity range, thus obviating the need for a prewash, and the vegetable oil industry has been considering the issue. FEDIOL (the European refiners association) have, however, recently advised that they are not prepared to alter the heating instructions in respect of vegetable oils. This will mean that a prewash is inevitable for a number of oils.
It should be noted that the revised Annex II requires that the prewash and discharge ashore should be carried out in the port of unloading unless a port that the vessel is due to call at later has confirmed in writing that it has a reception facility available that is adequate for the purpose. The unloaded tank must be neither washed nor ballasted at sea before the prewash can be carried out.
Prudent masters must ensure  the availability of shore reception facilities, till all are familiar will the new regulations.

Regarding the DH ( discharge temperature ), --for solidifying or high viscosity cargoes which have been identified as being required to be a certain minimum temperature during unloading--  If  P-Xylene was discharged at temperature of 17°C,  the tank cleaning slop of the cargo should be discharged to a reception facility because it is a solidifying cargo defined as Solidifying substance.

It means --in case of substances with melting points less than 15°C, is at a temperature, at the time of unloading, of less than 5°C above its melting point. 
  
Therefore the P-Xylene(melting point:13°C) with temperature of  more than18°C(13+5)  has   to be unloaded and then the tank cleaning slop of the cargo can be discharged into sea.

 
Category Z

Noxious Liquid Substances which, if discharged into the sea from tank cleaning or deballasting operations, are deemed to present a minor hazard to either marine resources or human health and therefore justify less stringent restrictions on the quality and quantity of the discharge into the marine environment;
Examples are  Acetone, Acetic acid, Dodecyl Benzene , Methyl Ethyl Ketone, MTBE, Phosphoric acid , Urea  etc.

For ships constructed before 1 January 2007 the discharge into the sea of residues of substances in Category Z or of those provisionally assessed as such or ballast water, tank washings or other mixtures containing such substances below the waterline is not mandatory.

If the unloading of a substance of Category Y or Z is not carried out in accordance with the Manual, a prewash shall be carried out before the ship leaves the port of unloading. Remember this relates to unpumpables due to heating breakdown ( cold interface etc ) and excess ROB due to use of PORTABLE FRAMO etc. The resulting tank washings of the prewash shall be discharged to a reception facility at the port of unloading or another port with a suitable reception facility provided that it has been confirmed in writing that a reception facility at that port is available and is adequate for such a purpose.

Every ship constructed on or after 1 July 1986 but before 1 January 2007 shall be provided with a pumping and piping arrangement to ensure that each tank certified for the carriage of substances in Category Z does not retain a quantity of residue in excess of 300 litres in the tank and its associated piping. If the stripping has failed or portable framo has been used for discharge due to deepwell pump failure , then the subject tanks have to be prewashed ( extended one ).

For a ship other than a chemical tanker constructed before 1 January 2007 which cannot meet the requirements for the pumping and piping arrangements for substances in Category Z referred to in paragraphs 1 and 2 of this regulation no quantity requirement shall apply. Compliance is deemed to be reached if the tank is emptied to the most practicable extent.  

Ships certified to carry substances of Category X, Y or Z shall have an underwater discharge outlet (or outlets).
For ships constructed before 1 January 2007 and certified to carry substances in Category Z an underwater discharge outlet is not mandatory.

          O    Other Substances:
                  Substances indicated as OS (Other Substances) in the pollution category column of chapter 18 of the International Bulk Chemical Code which have been evaluated and found to fall outside Category X, Y or Z because they are, at present, considered to present no harm to marine resources, human health, amenities or other legitimate uses of the sea when discharged into the sea from tank cleaning of deballasting operations. The discharge of bilge or ballast water or other residues or mixtures containing only substances referred to as “Other Substances” shall not be subject to any requirements of the Annex. The fourth category, OS (Other Substances), contains only 8 harmless products (apple juice, clay slurry, coal slurry, dextrose solution, glucose solution, kaoline slurry, molasses, water).

The revised annex includes a number of other significant changes. Improvements in ship technology, such as efficient stripping techniques, has made possible significantly lower permitted discharge levels of certain products which have been incorporated into Annex II. For ships constructed on or after 1 January 2007 the maximum permitted residue in the tank and its associated piping left after discharge will be set at a maximum of 75 litres for products in categories X, Y and Z - compared with previous limits which set a maximum of 100 or 300 litres (with 50 litres tolerance ), depending on the product category.

After 1st January 2007, all vegetable oils which is being currently listed in Chapter 18 of the IBC code ( meaning that they can be carried in normal product tankers with NLS certificate) can only be carried on type 2 chemical tankers. This means these cargoes will be transferred from Chapter 18 to Chapter 17.
Depth of water means the charted depth.

En route means that the ship is under way at sea on a course or courses, including deviation from the shortest direct route, which as far as practicable for navigational purposes, will cause any discharge to be spread over as great an area of the sea as is reasonable and practicable.

Liquid substances are those having a vapour pressure not exceeding 0.28 MPa absolute at a temperature of 37.8°C.
Nearest land. The term “from the nearest land” means from the baseline from which the territorial sea in question is established in accordance with international law

Noxious Liquid Substance means any substance indicated in the Pollution Category column of chapter 17 or 18 of the International Bulk Chemical Code or provisionally assessed under the provisions of regulation 6.3 as falling into Category X, Y or Z.

PPM means ml/m3.
Residue means any noxious liquid substance which remains for disposal.
Residue/water mixture means residue to which water has been added for any purpose

The discharge requirements of this Annex shall not apply to the discharge into the sea of Noxious Liquid Substances or mixtures containing such substances when such a discharge:
                  is necessary for the purpose of safety of a ship or saving life at sea; or
results from damage to a ship or its equipment:
provided that all reasonable precautions have been taken after the occurrence of the damage or discovery of the discharge for the purpose of preventing or minimizing the discharge; and
except if the owner or the master acted either with intent to cause damage, or recklessly and with knowledge that damage would probably result; or 
is approved by the Administration, when being used for the purpose of combating specific pollution incidents in order to minimize the damage from pollution. Any such discharge shall be subject to the approval of any Government in whose jurisdiction it is contemplated the discharge will occur.

Where the provisions in this regulation allow the discharge into the sea of residues of substances in Category X, Y or Z or of those provisionally assessed as such or ballast water, tank washings or other mixtures containing such substances the following discharge standards shall apply:
1              the ship is proceeding en route at a speed of at least 7 knots in the case of self-propelled ships or at least 4 knots in the case of ships which are not self-propelled;
2              the discharge is made below the waterline through the underwater discharge outlet(s) not exceeding the maximum rate for which the underwater discharge outlet(s) is (are) designed; ( use of UW discharge is not mandatory for category Z residues and tankwashings )
3              the discharge is made at a distance of not less than 12 nautical miles from the nearest land in a depth of water of not less than 25 metres.
4        Remark: the thing to note is that the discharge PPM is unrestricted after 1.1.07

For ships constructed before 1 January 2007 the discharge into the sea of residues of substances in Category Z or of those provisionally assessed as such or ballast water, tank washings or other mixtures containing such substances below the waterline is not mandatory.
For Category Z, regarding the distance of not less than 12 nautical miles from the nearest land for ships solely engaged in voyages within waters subject to the sovereignty or jurisdiction of the State the flag, of which, the ship is entitled to fly.

On request of the ship’s master an exemption for a prewash may be granted by the Government of the receiving Party, where it is satisfied that:
1              the unloaded tank is to be reloaded with the same substance or another substance compatible with the previous one and that the tank will not be washed or ballasted prior to loading; or
2              the unloaded tank is neither washed nor ballasted at sea. The prewash in accordance with the applicable paragraph of this regulation shall be carried out at another port provided that it has been confirmed in writing that a reception facility at that port is available and is adequate for such a purpose; or
3              the cargo residues will be removed by a ventilation procedure approved by the Administration
When a washing medium other than water, such as mineral oil or chlorinated solvent, is used instead of water to wash a tank, its discharge shall be governed by the provisions of either Annex I or Annex II, which would apply to the medium had it been carried as cargo.  Tank washing procedures involving the use of such a medium shall be set out in the Manual and be approved by the Administration.
When small amounts of cleaning additives (detergent products) are added to water in order to facilitate tank washing, no additives containing Pollution Category X components shall be used except those components that are readily biodegradable and present in a total concentration of less than 10% of the cleaning additive. No restrictions additional to those applicable to the tank due to the previous cargo shall apply.

Ballast introduced into a cargo tank which has been washed to such an extent that the ballast contains less than 1 ppm of the substance previously carried, may be discharged into the sea without regard to the discharge rate, ship’s speed and discharge outlet location, provided that the ship is not less than 12 miles from the nearest land and in water that is not less than 25 metres deep.

Cargo record book
After completion of any operation it shall be promptly recorded in the Cargo Record Book. In the event of an accidental discharge of a noxious liquid substance  an entry in ENGLISH  shall be made in the Cargo Record Book stating the circumstances of, and the reason for, the discharge.

Each entry shall be signed by the officer or officers in charge of the operation concerned and each page shall be signed by the master of the ship. The Cargo Record Book shall be kept in such a place as to be readily available for inspection .. It shall be retained for a period of three years after the last entry has been made.  The competent authority of the Government may inspect the Cargo Record Book on board any ship to which this Annex applies while the ship is in its port, and may make a copy of any entry in that book and may require the master of the ship to certify that the copy is a true copy of such entry. Any copy so made which has been certified by the master of the ship as a true copy of an entry in the ship’s Cargo Record Book shall be made admissible in any judicial proceedings as evidence of the facts stated in the entry.  The inspection of a Cargo Record Book and the taking of a certified copy by the competent authority under this paragraph shall be performed as expeditiously as possible without causing the ship to be unduly delayed.

The Government of each Party to the Convention shall appoint or authorize surveyors for the purpose of implementing this regulation. When a surveyor appointed or authorized by the Government of the Party to the Convention has verified that an operation has been carried out in accordance with the requirements of the Manual, or has granted an exemption for a prewash, then that surveyor shall make an appropriate entry in the Cargo Record Book.
 Where it is impracticable to measure the concentration of the substance in the effluent without causing undue delay to the ship,  the alternative procedure is for the surveyor to certify in the Cargo Record Book that:
1              the tank, its pump and piping systems have been emptied; and
2              the prewash has been carried out in accordance with the provisions of appendix 6 of this Annex; and
3              the tank washing resulting from such prewash have been discharged to a reception facility and the tank is empty.

Minimum quantity of water to be used in a prewash
The minimum quantity of water to be used in a prewash is determined by the residual quantity of noxious liquid substance in the tank, the tank size, the cargo properties, the permitted concentration in any subsequent wash water effluent, and the area of operation. The minimum quantity is given by the following formula:
Q=k(15r0.8 + 5r0.7 x V/1000)
                  where Q = the required minimum quantity in m3
                                     r =      the residual quantity per tank in m3. The value of r shall be the value demonstrated in the actual stripping efficiency test, but shall not be taken lower than 0.100 m3 for a tank volume of 500 m3 and above and 0.040 m3 for a tank volume of 100 m3 and below. For tank sizes between 100 m3 and 500 m3 the minimum value of r allowed to be used in the calculations is obtained by linear interpolation.
For Category X substances the value of r shall either be determined based on stripping tests according to the Manual, observing the lower limits as given above, or be taken to be 0.9 m3.
                                     V =    tank volume in m3
k =          a factor having values as follows:
Category X, non-Solidifying, Low-Viscosity Substance, k = 1.2
Category X, Solidifying or High-Viscosity Substance, k = 2.4
Category Y, non-Solidifying, Low-Viscosity Substance  k = 0.5
Category Y, Solidifying or High-Viscosity Substance, k = 1.0

The table below is calculated using the formula with a k factor of 1 and may be used as an easy reference.
Stripping quantity (m3)

Tank volume (m3)

100
500
3000
<0.04
1.2
2.9
5.4
.10
2.5
2.9
5.4
.30
5.9
6.8
12.2
.90
14.3
16.1
27.7

 Verification testing for approval of prewash volumes lower than those given in paragraph 20 may be carried out to the satisfaction of the Administration to prove that the requirements of regulation 13 are met, taking into account the substances the ship is certified to carry.  The prewash volume so verified shall be adjusted for other prewash conditions by application of the factor k as defined in paragraph.

               Ventilation of cargo residues from a tank :
High Volatile Cargoes with a VP>5000 Pa @ 20 deg c ( 50 mb @ 20 deg c ) that can be removed by ventilation.

                  1            the pipelines shall be drained and further cleared of liquid by means of ventilation equipment;
2              the list and trim shall be adjusted to the minimum levels possible so that evaporation of residues in the tank is enhanced;
3              ventilation equipment producing an airjet which can reach the tank bottom shall be used. Figure 7-1 could be used to evaluate the adequacy of ventilation equipment used for ventilating a tank of a given depth;
4              ventilation equipment shall be placed in the tank opening closest to the tank sump or suction point;
5              ventilation equipment shall, when practicable, be positioned so that the airjet is directed at the tank sump or suction point and impingement of the airjet on tank structural members is to be avoided as much as possible; and
6              ventilation shall continue until no visible remains of liquid can be observed in the tank. This shall be verified by a visual examination or an equivalent method.

The graph with inlet jet penetration depth in metres on X axis and minimum flow for each cargo tank in CUM/ min on Y axid is given in P&A manual—read off flow rate against linear lines for various inlet diameters

CARGO RECORD BOOK:--

Every chemical tanker is required to maintain a Cargo Record Book. This book must be upto date at all times.

In some ports (like in Algeria) the harbour master takes the cargo record book away while the ship is alongside and returns it just prior sailing . This is not allowed as per the regulations. Many ships are not familiar with  how to make correct entries in the Cargo Record Book .

Entries in the Cargo Record Book are required only for operations involving Categories X,Y,Z substances.  Other Substances carried in bulk are not subject to the provisions of this Annex as they are not in the Pollution Category column of chapters 17 of IBC Code and it is NOT necessary to enter in the Cargo Record Book (i.e.  Molasses, Clay slurry , Apple juice etc)

1.       The Cargo Record Book shall be completed, on a tank-to-tank basis, whenever any of the following operations
         with respect to a noxious liquid substance take place in the ship:

a). loading of cargo
b). internal transfer of cargo
c). unloading of cargo
d). cleaning of cargo tank
e). ballasting of cargo tanks
f). discharge of ballast from cargo tanks
g). disposal of residues to reception facilities
f). discharge into the sea or removal by ventilation of residues in accordance with regulation 5 of thisAnnex.  

2.       Each operation shall be fully recorded without delay in the Cargo Record Book so that all the entries in the book appropriate to that operation are completed as and when it happened.

3.       When making entries in the Cargo Record Book, the date, operational code and item number shall be inserted in the appropriate columns and the required particulars shall be recorded chronologically in the blank spaces without leaving blank spaces between last operation records and next operation records. 
 
4.        Each completed entry shall be signed by the officer in charge ( xxx ships Chief Officer ) and each completed page shall be countersigned by the master of the ship as soon as it is complete.

5.        Entries shall not be altered, erased, or cut in any case.  If correction has to be made, two lines shall be run through such entry, leaving the corrected part in legible state, with the signature of the officer affixed. No tipex white fluid corrector can be used.

6.       The cargo record book shall be retained for a period of three years after the last entry has been made.

Recapitulation:
Revised MARPOL & IBC Discharge & Stripping Requirements
Category
BCH Ships Constructed before 31/7/1986
Existing IBC Constructed from 31/7/1986 but before 1/1/2007
New Buildings Constructed from 1/1/2007
Ships Other than Chemical Tankers constructed before 1/1/2007
X
Pre Wash Strip to 350 Litres 12 mile 25m water depth 7 knots, en-route
Pre Wash Strip to 150 Litres 12 mile 25m water depth 7 knots, en-route
Pre Wash Strip to 75 Litres 12 mile 25m water depth 7 knots, en-route
Carriage Prohibited
Y
Pre Wash for solidifying for high viscosity substances Strip to 350 Litres 12 mile 25m water depth 7 knots, en-route
Pre Wash for solidifying for high viscosity substances Strip to 150 Litres 12 mile 25m water depth 7 knots, en-route
Pre Wash for solidifying for high viscosity substances Strip to 75 Litres 12 mile 25m water depth 7 knots, en-route
Carriage Prohibited
Z
Strip to 950 Litres 12 mile 25m water depth 7 knots, en-route
Strip to 350 Litres 12 mile 25m water depth 7 knots, en-route
Prewash if stripping not in accordance with P&A manual.
Strip to 75 Litres 12 mile 25m water depth 7 knots, en-route
Prewash if stripping not in accordance with P&A manual.
Strip to Maximum Extent 12 mile 25m water depth 7 knots, en-route
OS
No carriage Requirements
No Carriage Requirements
No Carriage Requirements

Underwater Discharge Required
Only X and Y cargoes
Only X and Y cargoes
X,Y and Z cargoes
Only X and Y cargoes


-------CAPT AJIT VADAKAYIL ( 28 YEARS IN COMMAND )--Rules as on end 2009