Module 2.1 Knowledge Questions

Question 1

lf after turning the gas emergency control off, the gas operative is still detecting a smell of gas, the action to take is: …………………………………………………….

Answer 1

Report the escape to the ESP and, if possible, remain on site until they arrive

Question 2

Which of the following instructions should not be given to a member of the public, who has reported a smell of gas within their property?

a Turn off the emergency/meter control.
b Extinguish all naked flames.
c Turn off all electrical switches.
d Ventilate the property by opening doors and windows.

Answer 2

c Turn off all electrical switches.

Question 3

A 0.01 % saturation of CO in the bloodstream (the point at which the first symptoms of CO poisoning occur) is equivalent to…..

a) 100 parts per million (ppm)
b) 1000 parts per million (ppm)
c) 10,000 parts per million (ppm)
d) 100,000 parts per million (ppm)

Answer 3

a) 100 parts per million (ppm)

Question 4

The approximate volumne fo air required for the complete combustion of 3m³ of natural gas is…

a) 20m³
b) 30m³
c) 40m³
d) 50m³

Answer 4

b) 30m³

Question 5

The Gross Calorific Value of Natural Gas is approx…

a) 38.6 MJ/m³
b) 93.1 MJ/m³
c) 121.8 MJ/m³
d) 212.4 MJ/m³

Answer 5

a) 38.6 MJ/m³

Question 6

Due to it’s density when natural gas is released in still air it will….

a) rise from the point of release
b) fall from the point of release
c) not leave the installation
d) freeze

Answer 6

a) rise from the point of release

Question 7

The Products of Combustion from a vitiated natural gas burner will contain…

a) Water vapour only
b) Carbon dioxide and water vapour only
c) Ozone
d) Carbon Monoxide and other products

Answer 7

d) Carbon Monoxide and other products

Question 8

The flame speed of natural gas is…..

a) 0.46m/s
b) 0.45m/s
c) 0.36m/s
d) 0.25m/s

Answer 8

c) 0.36m/s

Question 9

If during a routine visit a gas operative discovers a gas escape of 6mbar over a standard two minute test on the installation pipework, and the repair can not be made until the next day, the action required is:

a Turn off the gas at the meter control and arrange to repair next day.
b With the customer’s permission disconnect the supply, label and arrange to repair next day.
c Leave the supply on and ventilate the premises and arrange to repair next day.
d Contact the Gas Emergency Service and arrange to repair next day.

Answer 9

b With the customer’s permission disconnect the supply, label and arrange to repair next day.

Question 10

A standard atmospheric burner will comprise of…..

a) injector, fan, electrode and transformer
b) Mixing tube, lint arrester and venturi
c) Slide valve, fixed orifice jet and ignition leads
d) injector, venturi, mixing tube and burner head

Answer 10

d) injector, venturi, mixing tube and burner head

Question 11

CH₄ is the chemical symbol for….

a) All hydrocarbon fuels
b) Methane
c) Propoane
d) Butane

Answer 11

b) Methane

Question 12

The air that is taken by a burner flame in order to complete the combustion process is known as….

a) primary air
b) secondary air
c) tertiary air
d) adventitious air

Answer 12

b) secondary air

Question 13

The limits of flammability for natural gas are…

a) 2% to 10% gas in air
b) 2% to 9% gas in air
c) 5% to 15% air in gas
d) 5% to 15% gas in air

Answer 13

d) 5% to 15% gas in air

Question 14

A person suspected of suffering from the early stages of CO poisoning should be advised to…

a) stay inside and shut all doors and windows
b) shut down the appliance suspected of producing the CO and then go outside
c) get into the open air immediately and ventilate with pure oxygen if possible
d) stay inside until the doctor arrives

Answer 14

c) get into the open air immediately and ventilate with pure oxygen if possible

Question 15

Gas Safety (Installation and Use) Regulation 36 places the responsibility to act safely when discovering gas escapes upon:
a Gas Emergency Service Operative.
b All gas operatives.
c All members of the public.
d Anyone within a, b and c.

Answer 15

d Anyone within a, b and c.

Question 16

The type of burner which has approximately 50% of the total air added to the gas prior to combustion is called a..

a) bunsen burner
b) non-aerated burner
c) pre-aerated burner
d) post aerated burner

Answer 16

c) pre-aerated burner

Question 17

The approximate volume of Oxygen required for the complete combustion of 3m³ of natural gas is..

a) 2m³
b) 4m³
c) 6m³
d) 8m³

Answer 17

c) 6m³

Question 18

If the gas to a burner was supplied at a faster rate than it could burn the result would be ….

a) lightback
b) linting of the venturi
c) flame lift off
d) efficient combustion

Answer 18

c) flame lift off

Question 19

When a gas escape is reported to a gas operative by a member of the public, the gas operative, it unable to attend to the escape immediately, should:
a Instruct the member of the public to contact the Gas Emergency Service.
b Instruct the member of the public to turn of the gas at the meter control and report the escape to The Gas Emergency Service.
c Arrange to quote for the repair job as soon as possible.

d Contact the emergency services.

Answer 19

b Instruct the member of the public to turn of the gas at the meter control and report the escape to The Gas Emergency Service.

Question 20

The first priority when dealing with gas escapes is:

a Find the escape.

b Carry out a tightness test.

c Safeguard property.

d Safeguard life.

Answer 20

d Safeguard life.

Question 21

Carbon Monxoide is …

a) odourless, colourless and non toxic
b) colourless, odourless and extremely toxic
c) one of the deisred products of combustion
d) the name for the chemical symbol CO₂

Answer 21

b) colourless, odourless and extremely toxic