Core Concepts and Principles Flashcards
6 cards from real G3 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Core Concepts and Principles flashcards as text
What is the difference between complete and incomplete combustion?
Answer: Complete produces CO2 and water; incomplete produces CO and soot
Complete combustion produces CO2 and water; incomplete produces dangerous CO and soot due to insufficient oxygen.
What is the dew point in relation to gas appliance flue gases?
Answer: The temperature at which water vapour in flue gases condenses
The dew point is approximately 54°C (130°F) for natural gas combustion products.
What air-to-gas ratio is needed for complete combustion of natural gas?
Answer: 10:1
Approximately 10:1 (10 cubic feet of air per 1 cubic foot of gas) for stoichiometric combustion.
What is latent heat in the context of flue gases?
Answer: The heat released when water vapour in flue gases condenses
Latent heat is energy released when combustion water vapour condenses back to liquid.
What does absolute pressure mean in gas systems?
Answer: Gauge pressure plus atmospheric pressure
Absolute pressure equals gauge pressure plus atmospheric pressure (approximately 14.7 psi at sea level).
What is the Wobbe Index used for?
Answer: Measuring interchangeability of fuel gases based on heating value and specific gravity
The Wobbe Index relates heating value to specific gravity to determine gas interchangeability.