After you buy a car, you will install various automotive neighboring accessories.
You may install an aerosol-based fire extinguisher in the car.
You drive it in cold winter and hot summer.
But, question is, will it explode, especially in hot summer days?
China is suffering from the hot weather these days.
Many citizens have to park their vehicles outside in the summer days because the indoor parking area is occupied fully.
If you park a car under the sun for one hour in the summer days afternoon, you can’t even get in due to the burning temperature in the car.
I especially did a test at 12:00.
The temperature forecasted is 35°C at 12:00. I parked my car by the road, closed the window and measured the temperature.
The temperature was 28.8°C because the air conditioner was working before the engine went dead.
The temperature rose to 42.4°C in 10 minutes.
51.4°C in 30 minutes
and 63.1°C in 60 minutes.
Obviously, the temperature of all the subjects inside the car will also increase, including the aerosol-based fire extinguisher.
Let’s check it out.
There are many types of fire extinguishers in the market, like CARBON DIOXIDE, ABC powder, wet chemical, ect.
The aerosol-based fire extinguisher is bag on valve packaged, generally. It uses an aerosol can to contain the liquid content and the propellant gas for spraying. The feature is that it uses the BOV package.
Then, how is it manufactured?
First, you need to insert the bag on valve into the empty aerosol can.
Then, you fill propellant gas(Nitrogen) and seal the can under the gas filling & crimping head.
Last, you fill the liquid into the bag through the valve nipple.
I still don’t understand why it does not explode.
In fact, there are 2 factors to make it.
1. Nitrogen has a very small thermal expansion rate.
Nitrogen is a kind of inert gas. Its pressure is little influenced by temperature. Let’s take the aerosol fire stop spray for instance.
The inside total pressure after gas filling and liquid filling is 10 bar, and the temperature is about 26°C.
Now the temperature increases from 26°C to 75°C. There is totally 49°C temperature difference.
Let’s check out the pressure difference by the calculator.
There is only 26psi pressure increased.
2. The aerosol can is hard enough to withstand the pressure increase.
The fire extinguisher aerosol applies aluminum aerosol can. Its deformation pressure is usually 18bar and the burst pressure is 20bar.
Conclusion:
It is not a problem at all to put the fire extinguisher aerosol in the car. Actually, we tried to put the aerosol fire extinguisher in the cooker pan and oven ever for testing. And it did not explode.