Gas Fitter Practice Test

What is the name of the flame that results when there is no premixing of primary air with gas before ignition and appears yellow?

1. A Bunsen flame

2. A luminous flame

3. A gas starved flame

4. An air starved flame

The correct answer is: A luminous flame

A flame that results from the lack of premixing of primary air with gas before ignition is known as a luminous flame. This type of flame is characterized by its yellow appearance, which occurs due to incomplete combustion. In complete combustion, a blue flame is produced, indicating efficient fuel use and adequate air supply. However, when primary air isn’t mixed with gas before ignition, the combustion process is inefficient, leading to the production of soot and unburned hydrocarbons, which gives the flame its luminous, yellow color. This phenomenon is commonly observed in scenarios where there is insufficient oxygen, affecting the combustion process and leading to the visual characteristics of a luminous flame. Understanding the implications of flame color and type is vital in gas fitting, as it can indicate issues such as combustion efficiency and safety.