Which one of the following would be the best gas to use to zero the fixed oxygen analyzer monitoring an inert gas plant?

+nitrogen

What is the purpose of filling the free area of a cargo tank with inert gas?

* To remove the flammable atmosphere from the tank

When entering any part of the inert gas system to carry out maintenance or inspections, what is the main danger to life?

* Oxygen deficiency

What is inert gas?

* It is a gas containing insufficient oxygen to support the combustion of hydrocarbons

The regulations say that safely inerted gas mixtures should contain:

* Less than 8 % oxygen

When working in parts of the inert gas system such as the scrubber or deck water seal, what procedures must be followed?

* Enclosed space entry

What is the purpose of introducing inert gas into a cargo tank?

* To create a non*explosive atmosphere in the tank

What is the meaning of the expression “gas freeing”?

* To introduce fresh air into a tank

What is the meaning of the expression “purging”?

* To blow inert gas through the tank to reduce the oxygen or hydrocarbon gas level in an already inerted tank

What happens in the flue gas system if the pressure in the cargo tanks and Inert Gas Main becomes less than 50 mm Water Gauge during cargo discharge operations?

* Cargo pumps shutdown automatically

Which of these points (start up procedure) should be executed first?

* Open the flue gas*isolating valve

What is the maximum oxygen content of the inert gas delivered to the tanks?

* 5% by volume

How much time can it take before the oxygen analyser reading is accurate?

* Up to two hours

What are consequences of a ‘high-high’ oxygen content alarm sound during normal operation? This is when the oxygen content of the inert gas becomes more than 8 percent?

* The pressure control valve will automatically close, and the vent*to*atmosphere valve will open

During air venting/gas freeing of tanks the blowers draw air in from were?

* The blower fresh air inlet

Which of these points shall be executed last in the shut down procedure?

* Shut down inert gas blower

Are all pumps and blowers shut down during the shutdown procedure?

* No, the seawater pumps are left running

How often must the scrubber be flushed with water?

* Every time it is used

How often must the non-return valve be opened for internal inspection?

* Once a year/18 months

In a mixture of hydrocarbon gas and air, what does ‘Upper flammable limit’ UFL, mean?

* It is the point where the concentration of hydrocarbon vapour becomes too high to support combustion

In a mixture of hydrocarbon gas and air, what does ‘Lower flammable limit’ LFL, mean?

* It is the point where the concentration of hydrocarbon vapour becomes too low to support combustion