10 stycznia 2006 Albercik
GAS TANKER - ADVANCED
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ACTUAL GAS CARGOES
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1. Pyt. When was the transportation of liquefield gas in bulk started?
C Odp. Late in the 1920s.
2. Pyt. Where can we find relevant information regarding Constrution and Equipment of Ships
carrying Liquefield Gases in Bulk?
B Odp. In the IGC Code.
3. Pyt. Liquefield gas is,by IMO, divided in to differents groups.What is the criterion for this
division?
B Odp. The boiling point, chemical bindings, toxicity and flammability.
4. Pyt. What is the definition of LPG?
A Odp. Propane, butane and mixture of these.
GAS CARRIERS AND CARGO TANK COMPARTMENT
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1. Pyt. What is the minimum relieve valve setting on a fully pressurised gas carrier?
B Odp. The minimum relieve valve setting is equal to cargo temperature at 45oC.
2. Pyt. Are membrane tanks disigned for the carrying of ambient liquefied gases?
C Odp. No, membrane tanks are normally disigned for transport of fully refrigerated cargoes.
3. Pyt. Do we need insulation on cargo tanks on semi-refrigerated gas carries?
B Odp. Yes, to avoid cold cargo coming into contact with the ship construction.
4. Pyt. Can we load fully refrigerated propane directy into a fully pressurised gas carrier?
D Odp. Yes, if the cargo compartment is designed for temperature down to - 48oC.
FREIGHTING
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1. Pyt. In some cases the cargo is released without that the original Bill of Lading being
submitted at the discharging port.What is the common expression of this guarantee?
A Odp. A letter of Indemnity.
2. Pyt. Who are the parties involved in a negotation leading to a charter party?
A Odp. Ship owner, charterer and broker.
3. Pyt. Before commencing discharging in a destination port a certain documents has to be
handed over before the cargo is released.What is the name of this document?
B Odp. The original Bill of Lading.
4. Pyt. A charter party is an extensive documents with standard clauses which are usualy
supplemented with a "rider".What is a "rider"?
B Odp. Supplementary clauses.
CHEMISTRY AND PHYSICS
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1. Pyt. What is the ejectors normaly efficiency?
D Odp. Between 30%-40%.
2. Pyt. For what purpose do we have booster pumps on the cargo dischargeline on board gas
carriers?
C Odp. On gas carriers we have booster pumps on the cargo discharge line to increase the
discharge line presure above shore back presure.
3. Pyt. What kinds of pumps are used as main discharge pumps on gas carriers?
A Odp. On gas carriers multistage deepwell or submerged pumps are used main discharge
pumps.
4. Pyt. One of the pumps metioned below is without self-priming capacity.Whichones?
A Odp. Centrifugal pumps.
CARGO HANDLING EQUIPMENT
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1. Pyt. Which is the most utilised pump type used as discharge pump on gas carriers?
C Odp. Centrifugal pumps.
2. Pyt. Which type of piston compressor is most common as a cargo compresor?
A Odp. Double acting oil free piston compressors.
3. Pyt. What purpose has the disharge booster pump on a gas tanker?
A Odp. The main purpose of booster pumps is to increase the manifold presure.
4. Pyt. Which types of compressors are used as cargo compressors on board gas carriers?
A Odp. Piston, screw and centrifugal type compressors.
AUXILIARY SYSTEMS
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1. Pyt. What is the purpose of an automatic trip system on board, and how does this function?
B Odp. Automatic trip is to avoid tanks and pressurised vessels becoming overloaded, the trip
function is often initialised by a float switch.
2. Pyt. What kind of equipment is used to control the liquid level in the cargo tanks?
A Odp. In the cargo tanks we use either float or radar type gauges to control the liquid level.
3. Pyt. How does one prevent liquid from getting into the cargo compressor?
C Odp. By using a liquid receiver on the vapour line between the cargo tank and the cargo
compressor.
4. Pyt. Why are we not condensing the boil-off on board LNG carriers?
D Odp. We are not condensing the boil off on LNG carriers because of the energy consumption
needed to condensate the cargo.
GAS MEASUREMENTS
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1. Pyt. What temperature and pressure do IMO use to define liquefied gas?
B Odp. All chemicals witch excess pressure above 2,8 bar at 37,8 oC are liquefied gases.
2. Pyt. What toxic elements do we have in the ships inert gas?
A Odp. In the ships inert gas we have toxic elements such as Nitrogen oxide, sulphur dioxide
and Carbon monoxide.
3. Pyt. What do we mean by TLV when we talk about health hazards and cargoes?
D Odp. By TLV we mean Threshold Limit Value: that is the maximum number of hours we can
be in a given atmosphere daily.
4. Pyt. At what temperature do we take the read vapoyr pressure test?
D odp. At 37,8oC we take the read vapoyr pressure test.
SAFETY AND ENVIRONMENT
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1. Pyt. Where do we find information about the ships fire readiness?
C Odp. Information about the ships fire readiness is found in the alarm instruction.
2. Pyt. What are the citeria concerning automatic fire detection using heat/smoke detectors
and audio alarms on board a ships?
A Odp. All ships should comply with the SOLAS conventions.
3. Pyt. For what purpose do we have deck water spray on gas carriers?
D Odp. To flush cargo spill overboard, cool cargo area and protect crew in case of fire or
cargo spill.
4. Pyt. What IMO conventions deal with human safety at sea?
C Odp. The SOLAS conventions deal with human safety at sea.
CARGO PUMPS
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1. Pyt. What kinds of pumps are used as main discharge pumps on gas carriers as cargo
pumps?
C Odp. On gas carriers multistage deepwell or submerged pumps are used as main cargo pumps.
2. Pyt. What type of pump is used on gas carriers as cargo pumps?
A Odp. On cargo carriers centrifugal pumps are used as cargo pumps.
3. Pyt. What type of pump is mainly used on oil tankers as stripping pumps?
D Odp. On oil tankers an ejector is used as stripping pump.
4. Pyt. For what purpose do we have booster pumps on the cargo discharge line on board gas
carriers?
D Odp. On gas carriers we have booster pumps on the cargo discharge line to increase the
discharge line pressure above shore back pressure.
CARGO HANDLING ROUTINES
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1. Pyt. Which organisation establishes the minimum rules and regulations as used on gas
carriers?
A Odp. The IMO establishes all the minimum rules and regulations for gas carriers.
2. Pyt. How many tnternational conventions are there to protect the environment?
D Odp. There are three international conventions SOLAS, MARPOL 73/78 and STCW 78/95.
3. Pyt. How do we control the cargo tank pressure when loading a gas carrier?
C Odp. When loading we control the cargo tank pressure wich cargo compressors, vapor return
to shore or the loading rate.
4. Pyt. What is the maximum allowable filling limit on cargo tanks on gas carriers?
B Odp. Maximum allowable filing limit on caego tanks is 98% on gas carriers.
CARGO CALCULATION
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1. Pyt. What temperature do we calcuating on when loading clean cargoes?
A Odp. We calcuate the liquid weight at the actual cargo temperature.
2. Pyt. What do we mean by ROB when calcuating cargoes?
B Odp. By ROB we mean total cargo Remaining On Board.
3. Pyt. What is the maximum filing limit in a cargo tank according to the IGC code 15.1.1?
B Odp. 98% of the tank volume.
4. Pyt. What temperature do we calculate on when using the ASTM-IP tables?
D Odp. We calculate the liquid weight at 15oC.
COOLING PROCESSES AND CALCULATIONS
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1. Pyt. What gives the condenser pressure in a 1 stage direct cooling plant?
A Odp. It is the seawater temperature that gives the condenser pressure in a 1 stage direct
cooling plant.
2. Pyt. For what purpose are we using a molier diagram?
A Odp. We use the molier diagram to calculate the cooling capacity of the cooling plant.
3. Pyt. What is the main information we get from a molier diagram?
D Odp. We get information about enthalpy, specyfic volume of vapour, liquid/vapour mixture,
temperature of vapour when pressure is known etc.
4. Pyt. Why do we use oil free compressor on the cargo side in a cargo cooling plant?
A Odp. We use oil free compressor in the cargo side to avoid oil spill into the cargo.
INSULATION AND HEAT TRANSFER
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1. Pyt. What is the most common used insulation material on atmospheric pressure gas
carries?
A Odp. Expanded Perlite.
2. Pyt. How do we make polyurethane foam?
C Odp. By mixing isocyanate and payola.
3. Pyt. The thermal conductance capability is expresed by a materials thermal conductance
number and states the heat quantity.What is the denomination for heat quantity?
C Odp. Watts.
4. Pyt. What is the most frequent used insulation on cargo tanks?
C Odp. Polyurethane.
ASSESSMENT
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50 pytan - powtorka wszystkich poprzednich !