Propane Flashcards
What is the molecular formula of propane?
C₃H₈
What is the boiling point of propane at atmospheric pressure?
-44°F (-42°C)
What is the flashpoint of propane?
-156°F (-104°C)
Is propane heavier or lighter than air?
Heavier than air (vapor density = 1.52)
What is the flammable range of propane in air?
2.1% - 9.5%
What is the autoignition temperature of propane?
~896°F (~480°C)
What type of light or detection method cannot detect propane due to its ionization potential (IP)?
A photoionization detector (PID) cannot detect propane because its IP is 11.07 eV
How can mercaptans (odorant in propane) be detected using a PID?
Mercaptans have a lower ionization potential (IP) and may be visible on a PID lamp if within its range.
What is propane’s specific gravity as a liquid?
~0.5 (lighter than water)
What is propane’s behavior when released in water?
Propane is insoluble, floats on water, and quickly vaporizes.
Why is propane considered an asphyxiation hazard?
It displaces oxygen in enclosed spaces, leading to suffocation.
Why is propane classified as an explosive hazard?
Its low end flammable range make it highly prone to explosive ignition when mixed with air.
Can propane cause cold injury?
Yes-
Liquid propane can cause severe frostbite on contact due to rapid heat absorption during vaporization.
What are some of the common sizes of propane tanks?
20 lbs (grill), 33 lbs (forklift), 100 lbs (residential), and bulk tanks (250-1,000+ gallons)
What is the maximum fill percentage of a propane tank, and why?
80% to allow for thermal expansion and prevent overpressurization.
How is propane stored in a tank?
As a liquid under pressure with vapor on top.
What happens if a propane tank is exposed to fire without proper venting?
It can result in a BLEVE (Boiling Liquid Expanding Vapor Explosion).
What are propane tanks typically made of?
Steel or aluminum, designed for high-pressure containment.
What are the primary valves on a propane tank?
- Service valve: Supplies vapor or liquid propane to downstream equipment.
- Pressure relief valve (PRV): Releases propane if tank pressure exceeds safe limits.
- Fill valve: Used to fill the tank with liquid propane.
- Vapor return valve: Balances pressure during filling or transfers.
- Fixed liquid level gauge: Shows if the tank is at the correct fill level.
What is the function of the service valve?
Controls the release of propane to appliances or hoses.
What is the function of the pressure relief valve (PRV)?
Automatically vents propane to prevent overpressurization during overheating or overfilling.
What is the function of the fill valve?
Also called splash valve
Allows liquid propane to be introduced into the tank during refueling.
What is the function of the vapor return valve?
Used during filling to allow excess vapor to return to the source and prevent overpressurization.
What is the fixed liquid level gauge, and how is it used?
A small bleeder valve that emits liquid propane when the tank is filled to 80%, indicating a full tank.