Hose Test Burns

[Ten8_Ten19]

Anyone happen to see this story from the Flint Michigan Journal?

Firefighter now fighting burns: Veteran Davison chief recovering after being scaled by water

Sunday, August 26, 2001

.....During the past two-plus weeks, pain has riddled his body since a coupling came loose on a fire hose being pressure tested, dousing him with steaming-hot water.

...Wright called his experience a "freak accident." He had simply been walking past when the hose connection burst. The scalding water sprayed his left leg, ankles and other parts of his body, leaving second- and third-degree burns on nearly a third of his body.

First let me say that I wish Chief Wright a speedy recovery and I don't want to be hammered for questioning another department's procedures. That having been said, how could this have happened?

The news story ishere

[ADSNWFLD]

A few weeks ago I caught one of our less experienced firefighters testing hose with our lead engine. He was using tank water and wasn't circulating or dumping any water, and was about done with the 5 minutes at 250 psi. I touched the intake cap (to see if the pump was heating up) and almost burnt myself on the metal. I told him to shut down and when I opened the drains the water was actually steaming. So I find it easy to believe that some one could have received burns from a burst line.

Remember that water must be moving when using an engine to test with. Preferably hooked to a water source and dumping a little from a drain.

Stay safe

[Dalmatian90]

The Physics of the Situation...

The impeller is putting energy into the system (hose being tested, pump, etc)

Normally some of this energy is lost to friction, and a lot of the rest you feel as nozzle reaction. It also goes a bunch of other places, but those are two biggies.

Once you close the system, the Impeller is still putting just as much energy into it. The water isn't traveling anywhere, and it can't compress -- what does that energy do? It stores itself as heat!

I agree with ADSN/WNFLD -- keep them pumps circulating! It allows the pump dissipate the heat into the tank of water, instead of building it up.

[Ten8_Ten19]

I understand the physics. This is from the Deltahydro hose tester website

If a 1000 GPM, single stage pump were operated at a modest 200 PSI (hose is generally tested at 250 to 300 PSI), the 15 gallons of water it takes to fill the pump under static conditions would be heated at 35 degrees F. per minute. To put it another way, 70 degree water would be heated to 212 degrees and boil in less than four minutes. NFPA requires test times of five-minute cycles. The potential to damage the pump while testing fire hose is indisputable.

What I don't understand is how you can develop enough heat to inflict 2nd and 3rd degree burns without cooking the packing and seals out of the pump.

Is it acceptable to be recirculating during the test or should it be SOP to be hooked to a water source and flowing a little to a drain?

[Firebear230]

Whenever we hose test, we recirculate a little water to keep it cooler. Our new engine has a pump cooler valve on the panel that does the same job and doesn't take away from the hose testing.

[JoeMZ191]

You shouldn't need the pump engaged for the whole 5 minutes. I get it up to pressure, close the discharge, and give it a bump if the pressure drops below 250 psi.

I do understand ten8's question. I had a pump deadheading(I didn't know interior crews had put the hose down), and the pump packing blew steam out. Scared the hell out of me when it did. I think the Flint incident was probably caused by inattention and/or inexperience.

Joe

[Dalmatian90]

You could *easily* develop the temps in a pump to inflict 3rd degree burns without damaging the pump.

From http://www.cqc.state.ny.us/estime.htm :

Estimated Times/Temperatures Causing a Full Thickness (third degree) Burn in Children/Adults
For Adults
If the temperature is 160 degrees fahrenheit, it would take 1 second [to cause a third degree burn];
If the temperature is 149 degrees fahrenheit [common home boiler setting], it would take 2 seconds;
If the temperature is 140 degrees, it would take 5 seconds;
If the temperature is 133 degrees, it would take 16 seconds;


Those temps are far below boiling. Figure if you're wearing a regular duty or work clothes and 150 degree water hits you...it'll probably take you at least 5-6 seconds to strip out of them once you think about doing it -- probably more when you consider how hard soaking wet clothes are to get off. Meanwhile the clothing is holding the water on you continuing to transfer heat.