OT (hopefully) Fighting a petroleum-based fire---when to spray water AND dry powder

My son was over last night talking about his fire fighting training. He has been a firefighter for 6 years in a major city in the PNW and recently transferred to our local department. One thing we have in the area that he did not have previously is the presence of several large oil refineries. So, training on fighting those fires is important in the new job.

Yesterday his class went to a local refinery where they have an amazingly large training setup that can burn imperessive amounts of diesel (cheap if you are in the refinery business) and have folks on staff well-trained in putting out such fires.

A couple things he learned worth noting:
1) Dry chemical extinguishers work remarkably well on liquid petroleum fires. That he, like most people, knew before but got test them out on a larger scale than he previously had the opportunity to test.

2) The surprising tip he learned is that one can spray dry chemical into a stream of water played on a petroleum fire to amazingly good effect. That was demonstrated to him and he was impressed. One of the refinery workers related an experience where a local department was called to a farm tractor on fire due to a hydraulic line failure. The guys tried blasting it with water as it was too large to get close and, they thought, too large for a hand-held dry extinguisher. After 1000 gallons the fire was still going strong. Happening on the scene, the refinery fire fighter took a dry extinguisher and sprayed the powder into the stream of water---SNUFF!

At the refinery they have special nozzles to discharge dry chem into the water stream very efficiently. But, a garden hose and an extinguisher would work pretty well.

Good to know. Hopefully, none of us will need that info, but I doubt most of us would think of that potentially day-saving technique.

Denis

I heard on the radio a Bay Area fire fighter saying that the approved way to put out a EV car battery fire is water. I assume tesla had some input on this training. Car is not connected to ground through rubber tires so no electrocution hazard as long as they do not touch the car.
I did know clean distilled water is a good insulator. I do not think clean tap water is clean enough to be a good insulator.
Bil lD

Outstanding! Thanks for sharing.

As part of our safety training we were taught how to extinguish a diesel "burn pan" using a dry chemical unit but as the instructors pointed out that only works for small fires.

I hope I will never have to put that tip into practice but it has been stored in my memory banks ... just in case.

Bill D said:

I heard on the radio a Bay Area fire fighter saying that the approved way to put out a EV car battery fire is water. I assume tesla had some input on this training. Car is not connected to ground through rubber tires so no electrocution hazard as long as they do not touch the car.
I did know clean distilled water is a good insulator. I do not think clean tap water is clean enough to be a good insulator.
Bil lD

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The idea is to cool the battery pack to below the exothermic trigger point. Long before this type of battery was released out of the lab and into production researchers used reaction calorimeters to determine critical temperatures and pressures so they could limit charge and discharge to safe levels.

Scottl said:

Outstanding! Thanks for sharing.

As part of our safety training we were taught how to extinguish a diesel "burn pan" using a dry chemical unit but as the instructors pointed out that only works for small fires.

I hope I will never have to put that tip into practice but it has been stored in my memory banks ... just in case.

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Old story but still: one workplace I was at, had training for the lab occupants. They gave the lab folks CO2 bottles to apply to a burn pan like that, works OK until they slip a partly used CO2 unit to the next person in line. Fire is just about out, bottle runs dry, and the fire flares back up. Lesson: if the bottle is partly used up DON"T PUT IT BACK on the wall.

Then they give folks a dry chem unit to use. Five folks in line use the same dry chemical bottle to put the fire out, in turn. Lesson: if you really need to put out an oil fire, use the dry chem, damn the mess afterwards.

Bill D said:

I heard on the radio a Bay Area fire fighter saying that the approved way to put out a EV car battery fire is water. I assume tesla had some input on this training. Car is not connected to ground through rubber tires so no electrocution hazard as long as they do not touch the car.
I did know clean distilled water is a good insulator. I do not think clean tap water is clean enough to be a good insulator.
Bil lD

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The reason why water is safe as an electrocution hazard is that a turbulent stream isn't a good conductor even if the liquid is. The water separates into droplets with insulating air between them, so there isn't a single path through the stream for electricity to complete a circuit.

For EV, I thought water caused a violent exothermic reaction with the lithium in the batteries, maybe if you just keep going you'll use it all up and still keep the temperature under control with enough flow?

Foam....when applied correctly is the easiest way to extinguish a petroleum based fire, cafs systems are even better than the eductor style. Drychem can do well too. In training we used drychem vs gasoline to very good effect....picture a concrete mixing tub filled with gasoline.

For battery fires there are purpose built materials such as lith-x. You need a shit ton of water to even think of putting an electric car battery fire out.

I have watched them clean high tension insulators off from the ground with a firehose. I always assumed the power was off? Not needed back east were it rains year round.
Bill D

One tesla had a battery fire while driving. Tslea gave the driver anew car under warranty. They took it back when they looked closer and found out he had fired a gun into the battery while driving. I assume the metal bullet shorted the battery.
Bill D

plastikdreams said:

Foam....when applied correctly is the easiest way to extinguish a petroleum based fire, cafs systems are even better than the eductor style. Drychem can do well too. In training we used drychem vs gasoline to very good effect....picture a concrete mixing tub filled with gasoline.

For battery fires there are purpose built materials such as lith-x. You need a shit ton of water to even think of putting an electric car battery fire out.

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Yes, But I like the OP's posting, it's a helpful hint needed in an emergency.

Not everyone has foam equipment laying around, ready to go.

jim rozen said:

Old story but still: one workplace I was at, had training for the lab occupants. They gave the lab folks CO2 bottles to apply to a burn pan like that, works OK until they slip a partly used CO2 unit to the next person in line. Fire is just about out, bottle runs dry, and the fire flares back up. Lesson: if the bottle is partly used up DON"T PUT IT BACK on the wall.

Then they give folks a dry chem unit to use. Five folks in line use the same dry chemical bottle to put the fire out, in turn. Lesson: if you really need to put out an oil fire, use the dry chem, damn the mess afterwards.

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Exactly. Years ago while torching out a frozen shock absorber mount one of the rubber bushings caught fire. Without ant thought for the mess I hit it with the DC extinguisher which ALWAYS was within reach when using torches.

For those who don't know, most automotive rubber is petroleum based and burns ferociously once it ignites.

Asphalt too. These were from the Isaia thing this year:

Its also surprising how quickly ordinary plain dusty fine dirt will put out a fierce fire in a tractor.A few shovelfulls of dust ,and the flames are gone.

john.k said:

Its also surprising how quickly ordinary plain dusty fine dirt will put out a fierce fire in a tractor.A few shovelfulls of dust ,and the flames are gone.

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Yup, also pure oxygen.

I have been scrapping, get something burning, and blow it out with the torch.

Also, when using fire on a car (loosening up a rusty fitting, welding, etc.), keep a standard air blowgun handy.

I just saw a video of a fire co trying to put out a transformer on fire on a telephone pole. Went OK until the entire pole was wet to the ground, then the entire thing burst into flames & sort of exploded

Good knowledge to have! In my old shop, the neighboring operation ran oil in his CNCs instead of water soluble. One day it caught fire. He had a hell of time until someone showed up with an extinguisher that could handle it.

My last time at fire extinguisher training was several years ago. They had a pan that was like 3 foot square and 4-6" high that was half filled with heptane that they would light on fire for flammable liquid training. The first thing they do is give someone a plain water extinguisher and tell them to go at it after they light it. Of course this is to show what everyone knows - it won't work. Then they have the next person with either foam, dry chem or CO2 to put it out.

I had done the class several times and wanted to give it a shot with water to see if I could do it using better technique than just point and shoot like everyone does. So I went at it by rapidly moving the hose side to side to create more of a sheet of water. Well it started to work and the fire started to diminish as I kept approaching to keep attacking it. I ALMOST had it out and the extinguisher ran out. Dang!

The trainer was impressed I did that good, but the thing I learned is that you do have a shot if you really go at it and the fire is small and contained. Certainly not the best method, but if it is all you got it can at least buy you some time and you might get lucky. If someone else can grab a proper extinguisher, it might buy enough time to keep it in check, for example.

Just an interesting anecdote, IMO. I'd still grab the dry chem first if it happened for real.

Does water and C02 work?
Bob

CarbideBob said:

Does water and C02 work?
Bob

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It might be hail

Amusing story, fire training at a refinery, usual fuel pan thing, run hoses out
(There’s a right way, not mine!) hook foamant head and dip tube, shove in foamant container, spray foam, whole place like fish stinking sea foam gone mad, the trainer picked up his radio and Then told the pump house to start, we had been squirting at idle pressure, you could see the hoses (3” red flat things) straighten, I got dragged across the floor by the mad beast, man they take some holding, the foam squirted over 100 feet amazing, I stunk of fish for a week, we got to get lost in it, holding hands, you can breathe!, weird brown white silence in there, not nice
Mark