Tuesday, June 19, 2012

CHEMICAL TANKER THOUGHTS- CAPT AJIT VADAKAYIL



CHEMICAL TANKER THOUGHTS-  CAPT AJIT VADAKAYIL




In case of spill notify as per the ERP list—including the local P&I representative . Use the services of the agents for help in communications. Do not use dispersants till it has been approved by the local authorities.  In USA the OSRO is the NRC.



This company will not allow any ships officer to be victimized who slows down transfer or stops for imminent reasons of safety/ pollution.



All bolts used on the cargo system and manifold blanks must have 3 threads visible after complete tightening. Decanting annex one slops is prohibited in special areas. Separation can be hastened by controlled heating.



No class A products may be transferred if there are sources of ignition like car engines ( unless fitted with approved spark arrestor ) within 100 feet of ship. This rule may be ignored if both ship and shore jointly consider that there is no danger.



Requirements for limiting cargo rate and 30 minute moratorium for static charge is not required for inerted ships.



Radars with a peak pulse power output <60 KW do not present an ignition hazard from transmitted power recd by structures acting as aerials. If >60 then if freq is <700 MHz then safe dist is 300 Mtrs, if > 700 MHz then 150 Mtrs.



Swinging of lifeboats to embarkation  deck is allowed at sea—after Master makes a risk assessment..



Anchor is let go when ship has nil GPS speed—not Doppler speed.  Lay out cable 6 times the depth of water. Single engine helicopters must not be used for hovering over operations when flammable cargo is carried in inerted tanks. Tanks to be depresurised 30 min before.



When doing arc welding care should be taken not to overload the ships generators due to high starting current.



Running before sea on a small chemical tanker will small freeboard must be considered only if the crest to crest length of the waves is larger or smaller than the ships length and speed is reduced to 50% of wave speed.



When winds oppose currents very large freak waves are produced as off Agulhas, Gulf stream and East coast of Japan. Keep the ship well off the main axis of current ( especially if the shelf is steep ) which is given on the BA chart.




Standby generator must be taken on load at least 15 minutes before standby is given from bridge



Diesel engines must not be run for < 25% load for long periods to prevent fouling of Turbocharger and exhaust trunkings— follow the manufacturers instructions



Respiratory filters are of no use if oxygen content is < 20%--filters have exp dates –or 6 months after opening—even if not used. Organic filters are of no use against inorganic gases. Filters must not be used if gas conc is > 200 ppm, though they are effective to a max conc of 1000 ppm.



Drinking water must have a chlorine content of >0.2 ppm



Fire wire shall be rigged as per local regulations or 2 feet above water level.



The  Chief  Engineer  is  responsible for  maintenance  of  cargo  systems,  equipment  ,  instrumentation, tank cleaning systems etc and all defects shall be reported to him as soon as they are noticed.



The red light ( dangerous cargo ) is only for berth—at anchor it is NOT required. Do not energize radio equipment at berth unless authorized by master/ chief officer.



Notation must be made on deviation card of ships equipped with impressed current system if the equipment was on off while compensating compass. It must be switched off. Deviations with system on will vary with drafts , paint condition and electrical flow.



Silence of master means approval of pilots advise.



The master temperature/ pressure / loop calibrator must be kept in the safe custody of Chief engineer—who must be well versed with the equipment after reading the manual. Master gauges are for verifying the accuracy of test gauges and must not be used for anything else.



Colour heat exchangers black. Black is a good absorber and a good radiator. All chemical stocks must have the expiry dates on the sheet.



Electronic equipment is damaged by overheating. Make sure the air filters are cleaned regularly.



Air quality test of SCBA compressor must be done to check

Water vapour <50 mg/ cum

CO<5 ppm

CO2<500ppm

Oil mist<0.5mg/ cum



Flame screens are made from 28/28 guage to prevent the passage of flame through the mesh



The  exhaust  gas  boiler  circ  pump  must  be  run  for  at  least  3  hours  after  stopping  ME  to  prevent economizer fires and heat stress.



Do not touch metal cases of charged alkaline batteries.



Annual pressure test of cargo tanks and vent lines with p/v valves are to be carried out as follows:



Pressure test

Overhaul p/v valve

Put the valve manually in closed position

Connect air hose with calibrated pressure gauge to the vent line

Batten down the tank being tested , close all cargo valves, open the air and keep an eye on the pressure gauge. When pressure achieves 0.21 bar ( set pressure ) the p/v valve should open. If valve remains closed with pressure exceeding 0.21 bar, the valve requires repair. Don’t pressurise tank more than 0.3 bar.

Close  air  and  thoroughly  inspect  all  opening,  deck  above  the  tank,  vent  line.  If  you  don’t  hear  air leaks/hissing and pressure  0.21 bar remains stable during 30 min the tightness of the tank/lines is OK.



Vacum test



Usually p/v valve vacuum setting is 0.035 bar. The aim of testing is to check if   the valve opens at set vacuum.To test p/v valve for vacuum setting the following procedure is to be carried out:



Plug the vent line from the tank.

Connect Wilden pump or Graco barrel pump with   pressure/vacuum gauge to vent line and start pumping with slowest speed  to create vacuum in the line

Monitor the gauge and when vacuum (negative pressure ) reach 0.035 bar p/v valve should open. If valve remains closed at vacuum exceeding 0/035 bar, it needs repair



BUTTERFLY valves are insensible to solids pumped, maintenance costs are low as only gaskets/ seats has to be renewed. However the disadvantage is it is difficult to regulate a small flow through the valve like for gate valves. Never use reciprocating pumps for pressure testing as pressures become too high. Butterfly valves with ¼ turn open/ shut are ideal for auto use. The valve gate is in the centre and cause friction losses.

GLOBE valveliquid changes direction and causes friction losses.the pumping loss amounts to

60 metres of pipe. ( 6 metres for a gate valve )



No small craft or Tugs should be permitted alongside during operations, which involve venting of cargo vapour’s. No un-authorized craft to secure along side or approach close to the vessel without permission from the Terminal and / or the vessel’s representative.



Use company small craft alongside checklist. There should be adequate overside illumination for the craft alongside during the hours of darkness. Check that all small craft’s intending to come along side have adequate fendering to prevent damage. Duty Officer to ensure that “NO SMOKING, NAKED LIGHT & COOKING APPLIANCE” regulations are strictly enforced on the small craft’s when they are along side. Operations should be stopped immediately if these rules are violated and should not be started until the situation has been made safe.



Use of mechanically powered tools including grit blasting though not normally considered as hot work shall only be permitted under controlled conditions i.e. by using hot work permits. Cargo & inert gas pipelines shall not be blasted or mechanically chipped unless the entire ship is gas-free. Powered tools shall only be used after assimilating all information given in their respective manuals. Grit-blasting / spray painting equipment should be earthed.



Where the pumproom ventilation trunking incorporates emergency ventilation flaps (which permit ventilation of the pumproom in the event of flooding the lower pumproom) the remote operation of these flaps is to be tested and recorded.




Fire detector heads must be tested every 3 months as a cycle. To test use small canister Freon for ionization units, small electric heater ( or steam generator capsule ) for heat units and flashing light beam for infra red detector. Do not use a lighter or cigarette to show an inspector.



Pumproom and engine room foam system must be tested with water every 3 months. When demonstrating CO2 extinguisher the gas should not be released.



SCBA compressors must be overhauled annually and all filters replaced.  After that an air quality test must be conducted for Carbon Monoxide <5 ppm, Carbon di Oxide <450 ppm, and oil mist < 0.4 mg/ m3.



In case of PV fire during loading reduce rate to keep the flame just above the vent. Cut off/ quench the flame . Direct water to cool incendive spots and shut off loading. Flame screens are made with 28/ 28 guage to arrest flame.



For calibrating Oxygen analyzer use Nitrogen for zero check.



For calibrating Explosimeter –

% LEL—0.75% Pentane in air to give 50% LEL reading.



For calibrating tankscope--

% volume---7.5%  Butane in nitrogen—this gives a reading of 7.5%.



Respiratory filters are of no use if the oxygen content is less than 20%. Filters have expiry dates. Usuallly

6 months after opening it has expired even if not used.



Organic gas filters are no use against inorganic gases like Hydrogen Sulphide. Filters are not to be used if the gas concentration is greater than 200 ppm.



On chemical tankers who do wall wash it is Chief engineers responsibility to ensure the FWG water is of low chloride PPM.



Pipelines of Annex 1  cargoes must not be flushed into the sea , but into a cargo tank from where it can be transferred to slop tank.



Decanting of slops is prohibited in special areas. The separation of oil and water can be enhanced by controlled heating of dirty slop.



Use ODMCS of E/R bilges only in day time if possible.



SOLAS regulations require a pressure of minimum 100 m WG in cargo tanks at all times.



When discharging into barges remember there will be a siphoning action during the time between pump stop and close valve.



When arriving port the standby generator must be on load before engines are put on standby. Idle machinery like booster pump etc must be turned over once every 2 weeks.



Only daily use quantity of paint may be stored in the engine room.



Wall wash chemicals like Methanol which are flammable must be stowed outside the accommodation. Safe reserve of Heavy oil is 6 days for ocean voyages—take into account seasonal weather.



Number all flexible cargo hoses.



There must be a chart showing lubricant used displayed in the ECR/ CCR.



Soot blowers must not be operated in port . At sea the officer on bridge must be informed.



The economizer circ pump should be run for at least 2 hours more after stopping ME to prevent soot fires and heat stress..



Alkaline batteries eye wash is 0.5 ml of Boriacic powder with half litre of water. Do not operate tag anywhere must have date/ time/ authority



Changing bulbs in hazardous areas like paint locker,  require electrical work permit.



Calibrating thermometers and pressure gauges must have calibration certificates renewed every 2.5 years.



Master gauges are for verifying the accuracy of test gauges and must not be used for any other purpose. When doing arc welding care must be taken not to overload the ships generators due to high starting current.



If the plug material is different from the orifice   a protective coating of PTFE tape secured before replacing, to avoid galvanic corrosion.



Gaskets used in the cargo system shall be made of teflon or have a teflon jacket to protect it where it is likely to be in contact with the cargo.



Flame arresters and other small discharge orifices should never be painted.



Electrical Equipment



"Intrinsically safe" - an electrical circuit of connected apparatus and wiring in which no spark or thermal effect under normal operation or fault conditions is capable of causing ignition of a given explosive mixture achieved by using low power circuits having limited voltages and currents



"Flameproof Equipment" - equipment within an enclosure capable of withstanding the pressure  developed during an internal ignition of a flammable mixture such that any explosion generated products are cooled to below ignition temperature before reaching the surrounding atmosphere



Electrical equipment shall be de-energised and isolated before any maintenance is  commenced.

Isolated electrical supplies shall where possible have the fuses removed, be locked and tagged - the responsible person shall not permit isolated electrical supplies to be reconnected without ensuring that it is safe to do so.



High voltage test equipment - "megger testers" - shall only be used on circuits for which it is designed and must never be used on intrinsically safe/low voltage circuits which may be damaged by its use.



If internal condensation is observed within some equipment, it must be isolated and dried out. Design clearances of certified flameproof type enclosures shall be maintained at all times.



Under no circumstances is additional or modified electrical equipment to be fitted in cargo areas or area where flammable vapours are likely to be present without the approval of the Classification Society and the Company.





Safety devices fitted to the cargo system, control or alarm system, instrumentation system etc. must not be isolated, by-passed or have their settings changed without written authorization from the Master.



Filters of control and alarm systems must be maintained clean and fluid systems shall only be replenished using approved fluids compatible with cargo, gasket and sleeve materials as recommended by system's manufacturers.



Precision tools provided for the maintenance of instrumentation shall not be used for any other purpose. Pneumatic, electronic and other equipment provided to assist in defect identification shall only be used for its intended purpose.  

Instrumentation systems susceptible to interference from outside sources, e.g. portable radios, mobile phones , computers, etc. should be identified and procedures implemented to eliminate any interference to the systems.



For pipeline supports --where relative movement has been designed into the system, all moving surfaces must  be regularly cleaned and lubricated



-------CAPT AJIT VADAKAYIL

          (29 years in command)






18 comments:

  1. This comment has been removed by the author.

    ReplyDelete
  2. Respected sir,
    i m doing journal on nanomaterial coating on steel plate for analysis test.Initially i wanted to coat titanium oxide on steel plate but i found tiatnium oxide to be too epensive.while searching for coating of chromium oxide i discovered that japan had already submitted thison 1973.Could u suggest lesser cost nanomaterial available in south india for analysis.The major aim is to discover new properties of the coated material what others have not found.

    ReplyDelete
    Replies
    1. hi n,

      chromium oxide and phosphorous patina was discovered in India more than 2000 years ago.

      Punch into Google search-
      STAINLESS STEEL CHEMICALTANKERS SUS316LN VADAKAYIL

      capt ajit vadakayil
      ..

      Delete
    2. Thnk u sir,i read it.so should i proceed with coating of chromium oxide on stainless steel plates.u have mentioned SUS316LN hich is used in tankers.can i try it this coating on plates used for daily purpose(house) or should i buy a higher grade.

      Delete
  3. wat say sir?....waiting for your reply eagerly?can i do chromium oxide coating on stainless steel without nickel?it's quite urgent

    ReplyDelete
  4. hello sir,
    what happens if we mix chromium oxide and r134 freon gas.for vapour compression in refrigeration systems can we se this mixture.i have heard of r134a-copper oxide and r134a-al2o3.which mixture do u think will improve the coefficient of performance for refrigeration(cr2o3,al2o3 or copper oxide).sppose if i increase the length of capillary tubes and reduce the dia will the heat transfer increase?waiting for ur reply captain...

    ReplyDelete
  5. please do reply sir....waiting...patiently..i need it badly

    ReplyDelete
    Replies
    1. hi n

      talking about metallurgy to a person of your LEVEL of knowledge is indeed dangerous -- if not futile..

      first of all you need to know that if chromium oxide.

      so i suggest you learn that first.

      punch into google search-
      STAINLESS STEEL CHEMICALTANKERS SUS316LN VADAKAYIL

      you should by now have known why copper is used in refrigeration coils.

      or why aluminium was used in ammonia systems.

      suggest you learn some basics of refrigeration first.

      capt ajit vadakayil
      ..




      Delete
  6. hello sir,
    ha..ha....anyway thanks for your reply.i will takecare of that...i am going for nano copperoxide with r134a.they have done this...i wanted to try new...with cr2o3..from ur reply i can understand it's dangerous...i will refer about refrigeration.again thank u so much for the reply.

    ReplyDelete
  7. guruji, again a big shout out to you for your help and advice on my personal problem shared with you a month or so back. you were kind enough to devote me time and suggest me ways to make my marital life work and for that i am ever indebted.

    we are back on track and god willing expecting to conceive soon. we had regular intercourse days 8-19 to maximise chances of conception. anything else we should be worried about or consider?

    my wife is on the anaemic side with a low reading of 7.0 which we are working on through yoga and diet. her thyroid is about 2.54 which i have read you write is fine. will the latent problem of anaemia be something to worry about as far as conceiving and health of the new child is concerned?

    what are some of the first pregnancy that we should look forward to?

    convey my kind regards to your wife and sons. i wish them the best in life.

    inspired by you and thankful to you

    ॐ असतो मा सद्गमय ।
    तमसो मा ज्योतिर्गमय ।
    मृत्योर्मा अमृतं गमय

    ReplyDelete
    Replies
    1. hi s,

      keep faith in god till she misses her periods.

      capt ajit vadakayil
      ..

      Delete
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  11. Hi captainjii...
    Going to Khatu shyamji in rajasthan..
    We go to Khatu mandir in which all public goes.. but there is also praachin(old)mandir behind the famous Khatu mandir..it is situated in the back street just few metres. ..
    Which one is real sir.. Which temple is beneficial for us..

    ReplyDelete
  12. hi captain vadakil,
    i am marine under writer, and tanker master.

    good to know you tenchical experience in sulphuric acid alleged contamination claim on a 25 yr old ship with previous cargo carraige of rbd palmoelin.

    cargo loaded 1c,3c,

    3 c is discharges and colourless,

    however 1 c is reddish tinge seen visually.

    sampling claimed done as per sop.

    ships discharge structure is framo stype

    youy intial comments will be appreciated on sulphuric acid

    ReplyDelete
    Replies
    1. hi u,

      the stainless steel lining in 1c appears to be damaged ( probably sea water ingress ).

      http://ajitvadakayil.blogspot.in/2012/06/sulphuric-acid-carriage-dangers-on.html

      http://ajitvadakayil.blogspot.in/2010/04/passivation-on-stainless-steel-chemical.html

      http://ajitvadakayil.blogspot.in/2012/05/stainless-steel-chemicaltankers.html

      capt ajit vadakayil
      ..

      capt ajit vadakayil
      ..

      Delete