Home Ask The Haz Mat Guys ATHMG007 – Ask the Haz Mat Guys, Episode VII

ATHMG007 – Ask the Haz Mat Guys, Episode VII


In this episode, we answer the following questions:

  • Will vapors burn in a drum?
  • Why can’t I see propane tank levels with a TIC?
  • What are the differences between butane and isobutane?
  • Are Bob and Mike sexist?

Complete Show Notes

00:45 Question #1 – Will Vapors Burn in a Drum?

  • It’s possible to raise the temperature of kerosene beyond its 400 degrees Fahrenheit flash point when it’s in a drum – with no oxygen, it has nothing to burn
  • If you add oxygen back to the drum with a superheater, it will catch on fire – liquid boils to release the head pressure in the drum (Henry’s Law)
  • Flash point – something catches on fire, but stops burning almost immediately
  • Ignition point – something catches on fire and continues to burn
  • Spontaneous combustion point – totally unpredictable fire in terms of when it starts and how long it burns
  • Charles’s Law offsets the vacuum in the drum – the higher the temperature, the less powerful your vacuum on the head space

4:00 Question #2 – Why Can’t I See Propane Tank Levels with a TIC?

  • Thermal imaging cameras (TIC) sometimes let you see lines within a liquid container, but not always – usually depends on the location of the leak
  • Remember that it doesn’t show you temperatures, but rather differences in temperatures
  • This means there has to be some differential between the temperature of the liquid and the ambient temperature
  • The location of the leak also affects whether you can see propane tank levels
  • Leak location also helps you differentiate between liquid and gas leaks – you can have a leak coming from the vapor space or a leak coming from the liquid space
  • Leaks from the vapor space causes the liquid inside the cylinder to vaporize (thereby undergoing a phase change) inside the cylinder
  • Phase changes require a lot of heat, which causes the other liquid in the container to decrease in temperature as a result
  • All of these rules also apply to trying to read liquid levels in drums with a thermal imaging camera

8:05 Question #3 – What Are the Differences Between Butane and Isobutane?

  • Both are basic isomers of the alkanes – they have the same molecular weight, same amount of carbons, same amount of hydrogens, same formula, etc.
  • However, they differ in structure – the group is linked on the side of the molecule, which changes the geometry of the actual structure
  • When this happens, changes take place in the entire compound of isobutane – this can affect melting, flash points, boiling points, physical appearance, physical properties, etc.

9:45 Question #4 – Are Bob and Mike Sexist?

  • Two listeners (Jackie and Jane) requested that Bob and Mike start saying “firefighter” instead of “fireman” to be more inclusive of both genders
  • Victoria provides her perspective and discusses her background in male-dominated areas (like the military)
  • Both listeners have valid points, but they also don’t acknowledge the value of the podcast before launching into their criticism
  • We aren’t here to coddle anybody or make them feel good – if you don’t like us, turn us off

Have a question? Send an email to feedback@thehazmatguys.com or leave a message on our Haz Mat Guys comment hotline: 843-628-1484

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Author: The Hazmat Guys