LGTCO/LGTF - Liquefied Gas Tanker Cargo Operations Exit Exam Questions - Set 5

Question 1

What are Gas Hydrates in liquefied gas operations?

Accepted Answer

B: Solid crystalline compounds formed by the interaction of water and hydrocarbon gas at specific temperatures and pressures

Answer

A: A white powdery substance produced by the reaction of ammonia with carbon dioxide

Answer

C: Compounds formed by the chemical combination of cargo liquid with atmospheric oxygen

Answer

D: Polymerized chains of unsaturated alkene molecules

Question 2

What are Peroxides in chemical and gas cargo handling?

Accepted Answer

C: Unstable, shock-sensitive compounds formed by the reaction of cargo liquid or vapor with atmospheric oxygen

Answer

A: A white powdery substance produced by the reaction of ammonia with carbon dioxide

Answer

B: Compounds formed by the interaction of water and hydrocarbons at low temperatures

Answer

D: Non-flammable inert gases used for tank padding

Question 3

Liquefied gas cargo tank contents are bounded directly by the:

Accepted Answer

B: Primary barrier

Answer

A: Secondary barrier

Answer

C: Interbarrier space

Answer

D: Ship's inner hull

Question 4

A device used to determine the liquid-vapour interface during the ullaging of semi-pressurized and fully pressurized tanks is a:

Accepted Answer

D: Slip tube

Answer

A: Radar gauge

Answer

B: Float gauge

Answer

C: Capacitance gauge

Question 5

Which of the following is an example of a closed gauging system that does not penetrate the cargo tank shell?

Accepted Answer

C: Radar (microwave) gauge

Answer

A: Slip tube

Answer

B: Float gauge

Answer

D: Nitrogen bubbler gauge

Question 6

Where on a firefighter wearing SCBA is the fireproof 30-metre lifeline attached?

Accepted Answer

C: Attached by means of a snap hook to the harness of the apparatus, or to a separate safety belt

Answer

A: Tied around the waist

Answer

B: Tied to the SCBA air cylinder bottle

Answer

D: Tied securely around the wrist

Question 7

Which of the following is a solid desiccant medium that dries gas by adsorption of water molecules?

Accepted Answer

D: Activated alumina

Answer

A: Wood shavings

Answer

B: Cotton fiber

Answer

C: Activated carbon

Question 8

The temperature at which condensation will take place within a gas mixture if further cooling occurs is known as:

Accepted Answer

B: Dewpoint

Answer

A: Critical temperature

Answer

C: Absolute temperature

Answer

D: Flash point

Question 9

A gauging system employing a device which penetrates the tank and which, when in use, permits a small quantity of cargo vapour or liquid to escape to atmosphere is known as:

Accepted Answer

B: Closed device which penetrates the cargo tank

Answer

A: Closed device which does not penetrate the cargo tank

Answer

C: Restricted gauging device

Answer

D: Indirect gauging system

Question 10

Float gauges installed on liquefied gas tankers are an example of which gauging category?

Accepted Answer

B: Restricted gauging

Answer

A: Closed devices which do not penetrate the cargo tank

Answer

C: Closed devices which penetrate the cargo tank

Answer

D: Indirect ullage systems

Question 11

Semi-pressurized ships capable of withstanding carriage temperatures of down to -48°C are designed to carry which cargo?

Accepted Answer

D: LPG (Propane and Butane)

Answer

A: LNG

Answer

B: Ethylene

Answer

C: Ethane

Question 12

Semi-pressurized ships capable of withstanding carriage temperatures down to -104°C cannot carry which of the following cargoes?

Accepted Answer

A: Methane (LNG)

Answer

B: Propane

Answer

C: Butane

Answer

D: Ethylene

Question 13

In the case of a typical fully pressurized ship carrying cargo at ambient temperatures, what is the maximum design working pressure of the cargo tanks?

Accepted Answer

B: 18 barg

Answer

A: 0.7 barg

Answer

C: 5 to 7 barg

Answer

D: 9 barg

Question 14

The deepwell or submersible cargo pumps used for pumping liquefied gases are of which design type?

Accepted Answer

D: Centrifugal type

Answer

A: Rotary vane type

Answer

B: Gear type

Answer

C: Reciprocating piston type

Question 15

For a typical semi-pressurized ship, cargo tanks and associated equipment are designed for what working pressure?

Accepted Answer

A: Approximately 5 to 7 barg and a vacuum of 0.5 barg

Answer

B: Approximately 18 barg

Answer

C: Approximately 9 barg and a vacuum of 1.0 barg

Answer

D: Approximately 0.7 barg and a vacuum of 1.0 barg

Question 16

State the typical thickness of the primary metal membrane in membrane LNG tanks:

Accepted Answer

B: 0.7 to 1.5 mm thick

Answer

A: 2.0 to 3.7 mm thick

Answer

C: 4.0 to 5.0 mm thick

Answer

D: 8.5 to 10.0 mm thick

Question 17

State the carriage temperature for Propane at atmospheric pressure:

Accepted Answer

C: -42.3°C

Answer

A: -161.5°C

Answer

B: -88.6°C

Answer

D: -0.5°C

Question 18

State the carriage temperature for Ethylene Oxide at atmospheric pressure:

Accepted Answer

D: 10.7°C

Answer

A: 15.8°C

Answer

B: -7.2°C

Answer

C: -23.8°C

Question 19

State the carriage temperature for Propylene Oxide at atmospheric pressure:

Accepted Answer

B: 34.2°C

Answer

A: 9.6°C

Answer

C: -7.2°C

Answer

D: -10.2°C

Question 20

Dräger detector tubes and hand bellows pump are primarily used to measure which type of gas?

Accepted Answer

A: Toxic gas

Answer

B: Flammable gas % LEL

Answer

C: Oxygen percentage

Answer

D: Inert gas volume

Question 21

Which of the following liquefied gases is non-flammable?

Accepted Answer

A: Chlorine

Answer

B: Ethylene

Answer

C: Ethylene oxide

Answer

D: Propylene oxide

Question 22

Which of the following liquefied gases is categorized as toxic under the IGC Code?

Accepted Answer

C: Chlorine

Answer

A: Ethylene

Answer

B: Propylene

Answer

D: Methane

Question 23

The fixed gas-detection system's alarm on a gas carrier is activated when flammable vapour concentration reaches:

Accepted Answer

B: 30% of the Lower Explosive Limit (LEL)

Answer

A: 10% of the Lower Explosive Limit (LEL)

Answer

C: 20% of the Lower Explosive Limit (LEL)

Answer

D: 40% of the Lower Explosive Limit (LEL)

Question 24

Which statement correctly applies to Independent Type C cargo tanks?

Accepted Answer

B: No secondary barrier is required

Answer

A: A full secondary barrier is required

Answer

C: A partial secondary barrier in the form of a drip tray is always mandatory

Answer

D: Must be fitted with membrane insulation barriers

Question 25

For safe cargo tank entry, toxic gas concentration must be verified below:

Accepted Answer

C: Less than 50% of the OEL / TLV

Answer

A: Less than the OEL (Occupational Exposure Limit)

Answer

B: Less than 80% of the OEL

Answer

D: Less than 60% of the OEL

Question 26

What is the primary extinguishing chemical filled in an ABC-rated Dry Chemical Powder (DCP) extinguisher?

Accepted Answer

C: Mono-ammonium phosphate

Answer

A: Potassium bicarbonate

Answer

B: Sodium bicarbonate

Answer

D: Sodium, magnesium and aluminium powder

Question 27

What is the chemical powder filled in a standard BC-rated DCP fire extinguisher?

Accepted Answer

B: Sodium bicarbonate

Answer

A: Potassium bicarbonate urea

Answer

C: Mono-ammonium phosphate

Answer

D: Calcium hydroxide

Question 28

Under maritime international standards, what class of fire does a flammable gas fire fall under?

Accepted Answer

C: Class C fire

Answer

A: Class A fire

Answer

B: Class B fire

Answer

D: Class D fire

Question 29

Under maritime international standards, what class of fire does a flammable liquid fire fall under?

Accepted Answer

B: Class B fire

Answer

A: Class A fire

Answer

C: Class C fire

Answer

D: Class D fire

Question 30

What is the propellant gas used in fixed dry chemical powder (DCP) fire-fighting systems on gas carrier decks?

Accepted Answer

D: Nitrogen

Answer

A: Oxygen

Answer

B: Compressed atmospheric air

Answer

C: Acetylene

Liquefied Gas Tanker Cargo Operations (LGTCO/LGTF) (Set 5)

What are Gas Hydrates in liquefied gas operations?

Questions in LGTCO/LGTF Set 5

Question Discussion & Notes

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