1% AFFF foam used to extinguish crude oil fire

Boil over
On the 25th November 2010 DoseTech Special Risk Fire Protection met with the Milnerton Fire Department, Chevron Refinery Fire Team, Koeberg Nuclear power station fire team and various fire protection consultants and installers at the Koeberg power station fire training centre to demonstrate a crude oil boil over. 
For those of you who are not familiar with a boil over, it's pretty scary if you're not prepared for it.
The theory behind a boil over is that, when water enters a fuel storage tank, after some time it sinks to the bottom of the tank. The majority of fuel storage tanks have drainage points to remove this water but if too much water accumulates and a tank surface fire breaks out the water can be heated to the point of changing to steam. Once water turns to steam it expands 1600 times and the level of the fuel or oil in the storage tank is raised.

If the fuel level in the tank was high to start with the expanding steam can cause the tank to over flow and your surface fire quickly becomes a running fire. Not nice.

Our demonstration at Koeberg was a controlled boil over and as such we were well prepared for the expected results.
A 200L drum containing crude oil run off/slop was placed into a steel bund, approximately 2m x 2m, which was itself contained in a bricked bund area of 4m x 7m. 25L of water was added to the crude oil drum to form a layer of water in the bottom of the oil drum.
At 1PM on Thursday the 25th the surface of the oil drum was lit, with the help of some diesel poured on top of the oil, and the surface of the drum was allowed to burn. And for 40 minutes that's all it did.

At 42 minutes a crackling noise could be heard as the steam started to form and within a few seconds the crude oil started to boil over the side of the drum with spectacular efficiency. A roar of applause erupted from the gathered crowd as the fire continued to spread at a rate of knots.
Fortunately the Chevron Fire Department had matters well in hand and were prepared to extinguish.
We allowed the fire to burn for about another 2 minutes before starting to extinguish with a 1% AFFF Sthamex foam concentrate dosed into the water supply by our FD1000 adjustable FireDos foam pump. End of line the Firemen made use of our Akron Turbojet hand held nozzle complete with foam aeration tube. Water flow was set at 115 L/min.

Within 2 minutes 23 seconds the fire was out and we could breath a sigh of relief for a job well done.

Below are some photos of the boil over.

Mike Feldon
DoseTech (Pty) Ltd Managing Director
083 251 9346
mgf@dosetech.co.za

11th November 2010 - 1% & 3% foam tests at SAEC

Foam questions
So what's the real difference between 1% and 3% fire fighting foam concentrate? If you take a look at the base components, not much.
The major difference is that the 1% foam concentrate is simply more concentrated, if that makes sense.

As the various foam manufacturers have spent more time and money on R & D the manufacturing processes involved have improved dramatically allowing for more concentrated concentrates. As has been the case with 3% foams replacing 6% foams, for the most part, 1% foams are now beginning to replace 3% foams.
The benefits are vast, not the least of which being the foam storage tank size reduction by 2 thirds. For stainless steel tanks this translates into big money.

But the big question is of course, "Are the 1% concentrates as effective as their 3% or 6% counterparts?" The answer is yes but saying so is not always enough, we need some tangible evidence.

On the 11th November 2010 DoseTech Special Risk Fire Protection and Chemserve Systems gathered at the SAEC training school in Modderfontein to test the efficacy bot the 1% and 3% Dr Sthamer SThamex AFFF foam concentrates through a series of burn tests.

The criterea for the burn tests were as follows: 4 separate burns in the SEAC's 4,5M x 4,5m burn pan filled with Jet A1 fuel and the centre drum of the burn pan filled with tyres and wooden pallets. The fire would be lit from the centre, pallets and tyres first, and a 3 minute pre burn would be allowed for. Each burn was to be extinguished with a different agent and the results would be timed. The foam extinguishing tests would make use of our FD1000 adjustable FireDos proportional foam dosing pump and the end of line equipment would be our Akron Turbojet 1720 nozzle/branch complete with medium expansion foam aeration tube set at 115 L/min.

Burn test 1 was to test the effect of water only on the fire. This did not go particularly well and after 3 minutes the fire died out, more from the fuel burning off than the water being effective.

For burn test 2 our FireDos was set to admix an A class wetting agent manufactured by Chemserve, Flameblock, at 0.3%. The results from this test were slightly better with a total extinguishing time of 2 minutes 30 sec.

Test 3 was with our FireDos set at 3% admix rate to ad the 3% Sthamex AFFF to the fire fighting water supply. This test went extremely well with all signs of flame being out in 30 seconds flat. A nice aqueous film was formed over the Jet A1 fuel smothering out all oxygen.
 Now for the big one, burn test 4 with a 1% Sthamex AFFF foam concentrate. With the FireDos set to 1% Johan of the SAEC began to fight the fire. If you'd blinked you would've missed it as the fire was out in 27 seconds, almost the exact same result as the 3% Sthamex AFFF. A good result all round.

After a quick clean up and congratulations all round we headed for the bar, a converted half fire truck in this case. Thanks again to Jan of the SAEC for allowing the use of his fantastic facility. Below are some photos.

Test team relaxing afterward

Mike Feldon

DoseTech Managing Director

083 251 9346

mgf@dosetech.co.za

Akron & Scotty Fire foam demo

Earlier today we spent some time with the Milnerton Fire department, Cape Town, who were kind enough to offer their facility for some new product demonstrations.
We tested our new Akron Branches, Turbojet and Saberjet, with medium expansion foam tubes and all present were impressed with the quality of foam that was achieved.
Chemserve, local manufacturers of Dr Sthamer foam concentrate, joined us with their RLF4 training foam which we put to good use. Below are some photos of the tests.

As part of the test we had our Scotty foam bag backpack system on dispay which also perfomed well at a low admix rate of 1%, perfect for bushfire applications.

Mike Feldon

DoseTech Manager Director

083 251 9346