CHEMCO - Advanced Training for Chemical Tanker Cargo Operations Exit Exam Questions - Set 8

Question 1

Typically nitrogen contained in inert gas generated from boiler flue gas, at the scrubber outlet is

Accepted Answer

D: 83%

Answer

A: 50%

Answer

B: 60%

Answer

C: 70%

Question 2

Which statement about inert gas pressures in a cargo tank is TRUE?

Accepted Answer

B: Gas pressures should be maintained at the highest permissible level throughout the discharging process.

Answer

A: The pressures of the inert gas in the tank may create excessive pressure at the pump while discharging.

Answer

C: High gas pressures may cause pyrophoric oxidation in the tank.

Answer

D: High gas pressures may cause loss of suction when stripping.

Question 3

The purpose of the deck seal in an inert gas system is to prevent

Accepted Answer

A: flammable vapors from entering machinery space

Answer

B: flue gas escaping to atmosphere

Answer

C: inert gas escaping to atmosphere

Answer

D: air entering inert gas system

Question 4

After the initial cleaning of flue gas in an inert gas system the gas is passed through what device for final cleaning?

Accepted Answer

B: Demister

Answer

A: Scrubber

Answer

C: Deck water seal

Answer

D: Final filter

Question 5

The "flammable limits" of an atmosphere are the

Accepted Answer

B: upper and lower percentage of vapor concentrations in an atmosphere which will burn if an ignition source is present

Answer

A: two temperatures between which an atmosphere will self ignite

Answer

C: upper and lower pressures between which an atmosphere will not burn

Answer

D: two temperatures between which an atmosphere will burn if an ignition source is present

Question 6

Flue gas is drawn from the boiler uptake and delivered to the inert gas scrubber by a:

Accepted Answer

B: High capacity fan

Answer

A: Exhaust gas pressure from the stack

Answer

C: Inert gas compressor

Answer

D: Natural aspiration

Question 7

What is the major function of the deck water seal in an inert gas system?

Accepted Answer

B: Isolates hazardous areas from nonhazardous areas.

Answer

A: Relieves excessive pressures from the system.

Answer

C: Prevents the flow of inert gas into closed or isolated tanks.

Answer

D: Removes any leftover water or soot after the gas has been scrubbed.

Question 8

Inert gas systems must be capable of delivering inert gas with an oxygen content by volume in the inert gas main of not more than

Accepted Answer

B: 5%

Answer

A: 2%

Answer

C: 8%

Answer

D: 11%

Question 9

On a hydrocarbon flammability chart the line which extends from 0% to 21.8% oxygen, lying tangent to the flammability range, is called the

Accepted Answer

C: critical dilution line

Answer

A: minimum oxygen content line upper threshold limit

Answer

B: critical displacement line

Answer

D: upper threshold limit

Question 10

The component in an inert gas system used for cleaning the gas of solid and sulfur combustion products, while simultaneously cooling the inert gas, is called the

Accepted Answer

C: scrubber

Answer

A: filter

Answer

B: cooler

Answer

D: purifier

Question 11

Inert gas systems must be capable of maintaining inert gas with an oxygen content by volume in the cargo tanks of not more than

Accepted Answer

C: 8%

Answer

A: 2%

Answer

B: 5%

Answer

D: 11%

Question 12

You are discharging cargo and the inert gas system is in operation to inert the tanks. The pressure in a tank being discharged starts to drop below the allowable limit. What action should you take?

Accepted Answer

B: Open the pressure control valve until the pressure increases.

Answer

A: Cut in another IG fan to increase gas flow.

Answer

C: Open the tank isolation valve to the fully open position.

Answer

D: Reduce the pumping rate.

Question 13

The fresh air intake of the inert gas system

Accepted Answer

B: allows the inert gas piping to be used for gas freeing the tanks

Answer

A: prevents the flue gas from falling below an oxygen content of 3%

Answer

C: opens when there is excessive vacuum on the deck water seal

Answer

D: enables outside air to mix with and to cool the hot flue gasses

Question 14

What is the maximum oxygen content below which flaming combustion will no longer occur?

Accepted Answer

B: 8%

Answer

A: 5%

Answer

C: 10%

Answer

D: 12%

Question 15

The oxygen level in the tank is reduced by ________.

Accepted Answer

A: Inert gas system

Answer

B: High Expansion foam system

Answer

C: CO2 sytem

Question 16

In which of the following conditions, the IG blower fans should shut down automatically?

Accepted Answer

D: High scrubber water level

Answer

A: Oxygen content above 8%

Answer

B: Low water level in deck seal

Answer

C: Low water level in the scrubber tower

Question 17

What type of liquid is used in the liquid P/V breaker?

Accepted Answer

B: Water-antifreeze mixture

Answer

A: Hydraulic oil

Answer

C: Distilled water

Answer

D: Oil from the cargo

Question 18

What is the maximum percent of oxygen, by volume, allowed to be maintained in the cargo tanks prior to the commencement of crude oil tank washing?

Accepted Answer

B: 8%

Answer

A: 5%

Answer

C: 10%

Answer

D: 12%

Question 19

Checks to be done, amongst others, before and during COW are listed; identify the most important safety check

Accepted Answer

C: Inert gas in tank to be checked – (Oxygen to be less than 8%), IG pressure to be satisfactory (positive pressure)

Answer

A: When carrying out crude oil washing during cargo discharge, the Master should inform the terminal competent authority 24 hours before commencement (or other ship when ship-to-ship transfer is involved)

Answer

B: The Oxygen analyzing equipment to be tested and working satisfactorily

Answer

D: All hydrant valves on the tank washing line to be shut

Question 20

Concurrent COW with cargo discharge: identify the precaution for the Concurrent COW method for use

Accepted Answer

C: COW concurrent method: The normal minimum back pressure required for the operation of the COW guns is 8 kg/cm2.

Answer

A: COW concurrent method utilizes the crude oil stream being discharged, together with its associated back pressure, to supply the COW pipeline with crude oil.

Answer

B: COW concurrent method can be achieved either by a "bleed-off' system from the main crude oil discharge pipelines for supply to the COW pipeline or by separate supply using a designated cargo pump.

Answer

D: COW concurrent method: If supply is achieved by the bleed-off from the bulk discharge, then sufficient back pressure has to be maintained at all times.

Question 21

When evacuating a seaman by helicopter lift, the vessel should be__________.

Accepted Answer

C: underway with the wind 30° on the bow

Answer

A: stopped with the wind dead ahead

Answer

B: stopped with the wind on the beam

Answer

D: underway on a course to provide no apparent wind

Question 22

A rescue helicopter's hoist area should have a radius of at least __________.

Accepted Answer

D: 50 feet of clear deck

Answer

A: 6 feet of clear deck

Answer

B: 10 feet of clear deck

Answer

C: 25 feet of clear deck

Question 23

Usually the most gentle way of riding out a severe storm on a larger vessel is__________.

Accepted Answer

C: running before the seas

Answer

A: head on at slow speeds

Answer

B: hove to

Answer

D: to rig a sea anchor

Question 24

Your vessel is off a lee shore in heavy weather and laboring. Which action should you take?

Accepted Answer

A: Put the sea and wind about two points on either bow and reduce speed.

Answer

B: Heave to in the trough of the sea.

Answer

C: Put the sea and wind on either quarter and proceed at increased speed.

Answer

D: Put the bow directly into the sea and proceed at full speed.

Question 25

You are steaming in a heavy gale and find it necessary to heave to. Under most circumstances, this is best done by __________.

Accepted Answer

C: taking the sea fine on the bow and reducing the speed to the minimum to hold that position

Answer

A: stopping the engines and drifting beam to the seas

Answer

B: going slow astern and taking the seas on the quarter

Answer

D: maintaining speed and taking the sea broad on the bow

Question 26

Ice blink is__________.

Accepted Answer

C: the yellowish-white glare on the underside of a cloud layer water sky

Answer

A: the dark appearance of the underside of a cloud layer due to reflection of a surface of open water

Answer

B: the soft light appearance on the underside of a cloud layer due to reflection from a surface of open water

Question 27

Snow has obliterated surface features and the sky is covered with uniform, altostratus clouds. There are no shadows and the horizon has disappeared. What is this condition called?

Accepted Answer

B: Whiteout

Answer

A: Ice blink

Answer

C: Water sky

Answer

D: Aurora reflection

Question 28

A vessel is wind rode when it is __________.

Accepted Answer

A: at anchor and heading into the wind

Answer

B: backing into the wind

Answer

C: carrying lee rudder

Answer

D: necessary to apply a leeway correction to the course

Question 29

When evacuating a seaman by helicopter lift, which course should the ship take?

Accepted Answer

B: A course that will keep a free flow of air, clear of smoke, over the hoist area.

Answer

A: Downwind so that the apparent wind is close to nil.

Answer

C: A course that will have the hoist area in the lee of the superstructure.

Answer

D: With the wind dead ahead because the helicopter is more maneuverable when going into the wind.

Question 30

When the gyro-pilot is used for steering, what control is adjusted to compensate for varying sea conditions?

Accepted Answer

D: Weather adjustment

Answer

A: Rudder control

Answer

B: Sea control

Answer

C: Lost motion adjustment

Advanced Training for Chemical Tanker Cargo Operations (CHEMCO) (Set 8)

Typically nitrogen contained in inert gas generated from boiler flue gas, at the scrubber outlet is

Questions in CHEMCO Set 8

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