Flashcards: 7th ed

Chapter 1 Gas Fuels 1. The specific gravity of propane results in: quick dasipation. b. high ignition temperature. c. high flammability limits. d. pooling

2. Which of the following statements is true about the relationship between natural gas and propane a. Natural gas has a higher heat value than propane b. Propane has a higher ignition temperature than natural gas Propane has a higher specific gravity than natural gas d. Natural gas requires a higher air to fuel ratio than propane

3. What is the ideal combustion ratio for natural gas combustion? 4 to 1 b. 10 to 1 14 to 1 d. 24 to 1 Correct answer b 4. What is the term used to describe the percentage of fuel gas in the fuel and air mixture that will support combustion? a. Heat value b. Flammability limits c. Ignition temperature d. Specific gravity

Aldehydes b. Mercaptan Sulfur d. Methane

Chapter 2 | Principles of Combustion 1. Which of the following statements is true about carbon monoxide (CO) detection? The presence of aldehydes does not necessarily mean that CO is present. b. CO can be present without the detection by smell of aldehydes. CO is never present when aldehydes are detected. d. The presence of aldehydes will cause a residential CO monitor to alarm.

2. Which of the following is responsible for producing yellow flame in gas hearth appliances? a. Increased primary ait, reduced secondary air b. Reduced primary ait, increased secondary air c. Reduced primary air, reduced secondary air d. Increased primary air, increased secondary air

3. A 30,000 Btu appliance is installed at an elevation of 5,000 feet above sea level. The manufacturer requires a derating of 4% for each 1,000 feet above sea level for appliances installed higher than 2,000 feet above sea level. What is the proper Btu input of the appliance for this installation? a. 24,000 b. 26.400 c. 28,800 d. 30.000 Correct answer a 4. Which of the following catt result from incomplete combustion? a. Lower ignition temperature b. Soot c. Improved efficiency d. Lower carbon monoxide

Review Question Answers Chapter 3 | Fuel Gas Delivery 1. A customer calls to complain that his 40,000 Btu/hr propane hearth appliance is pe is performing below normal. The outside temperature is 32° F (0° C). Which of the following best explains the hearth appliance's performance? a. In cold weather, propane moves more slowly from the storage tank to the appliance. b. If the fuel level in the tank is low in cold weather, the vaporizing capacity of the tank may not be equal to the Btu/hr capacity. c. When the outside temperature reaches 32° F (0° C). propane freezes and vaporizing capacity ends. d. The "wetted surface of a storage tank is ineffective when the outside temperature reaches 32" F (0° C).

2. What is the typical residential delivery pressure for a LP regulator? a. 3-6" WC b. 7-10 WC c. 11-14" WC d. 15-18" WC

Chapter 4 | Gas Piping Guidelines 1. Which of the following diagrams shows the correct configuration for a sediment trap installation in a gas supply system?

コー 2. Which of the following is NOT acceptable electrical grounding and bonding for gas piping according to the fuel gas codes? a. Corrugated stainless-steel tubing (CSST) bonded to electrical service grounding system at the point where the gas service enters the building b. Rigid gas piping used as a grounding conductor c. Pipe bonded through connection to appliances connected to grounding conductor of circuit supplying the appliance. d. 6 AWG copper wire used for CSST bonding

3. Which of the following is NOT a factor that can influence gas pipe sizing when using the Longest Run Method? a. Heat value of the gas b. Number of 90 bends c. Specific gravity d. Pressure losses through sections of piping

4. Which of the following statements about leak detection is FALSE a. Electronic sniffers are sensitive to combustible gases other than natural and LP gases. b. Soapy water solutions may cause corrosion. c. Leak detection procedures are only necessary if gas is smelled. d. Fittings that are disturbed during installation and service should be leak tested.