phase4.mod3.comb

A vitiated air supply will produce carbon monoxide when the combustion of natural gas takes place within a space heater. What is Vitiated air?

which of the following is the minimum concentration of carbon monoxide within the air that will cause occupants to fall victim to coma within a few minutes?

• 0.05%.

• 0.4%.

• 0.8%.

• 1.0%.

Co tests on appliances other than gas cookers should be stopped and the area immediately ventilated and vacated if the CO reading exceeds:

• 10ppm.

• 15ppm.

• 20ppm.

• 30ppm.

What is likely to be the consequence of blocked air inlet grills of an open flued appliance?

Which type of flame is luminous and ragged in shape when working correctly?

The main constituent of natural gas is the hydrocarbon gas methane. Which of the following is a Hydrocarbon Fuel?

• Carbon monoxide.

• Carbon Dioxide.

• Butane.

• Nitrogen.

When completing a combustion analysis procedure to detect any presence of CO migration from other sources, over how long a period should the level of CO be monitored?

• 5 minutes.

• 10 minutes.

• 15 minutes.

• 20 minutes.

Which of the following percentages of gas to air will not support the combustion of natural gas?

• 6% gas in air

• 10% gas in air

• 14% gas in air

• 20% gas in air

What is the approximate quantity of primary air that will be entrained by a pre aerated flame?

• 25%

• 50%

• 75%

• 100%

Flame impingement can cause the production of carbon monoxide during combustion of natural gas. Flame impingement can be caused by:

• Incorrect positioning of a burner.

• Inadequate ventilation air.

• Excessive ventilation air.

• Reduced burner pressure.