Domestic Gas

What is the Specific Gravity of Natural Gas

• 0.60

• 1.0

• 1.5

• 2

What is the Gas Air Ratio for Natural Gas

• 38.5

• 9.8:1

• 21

• 30.9:1

What is CH₄ ?

• Butane

• Propane

• Ethane

• Methane

What colour is a Post-aerated flame?

• Blue

• Orange

• Yellow

• Purple

What does 'Pre' mean?

• Pre-demand

• After

• Before

• Often

Definition of Open Flue

• Air is taken for combustion from outside air and products of combustion is placed into an adjoining room

• Air is taken from within the room and placed back into the same room

• Air is taken from the room and PoC is placed via a purpose provided flue to the outside air

• Air is taken from the room and scrubbed clean before being expelled to outside air

What is the function of a DDD?

• Prevent downdraught from extinguishing the flame

• Prevent downdraught from extinguishing the flame and prevent up-pull of the gas

• Prevent downdraught from extinguishing the flame and help dilute the PoC

• Prevent downdraught from extinguishing the flame and ventilate the main gas burner

Carbon Monoxide (CO) at a volume % CO in blood 85-90 kills in ?

• 1 hour

• 3 hours

• 15 to 30 minutes minutes

• 1 to 3 minutes

What type of flue system is shown?

• SE Duct

• U Duct

• Vertex

• Open Flue

How many Starter Blocks are required in a block Chimney?

• 1

• 2

• 3

• 4