TFT Nozzle Test

Video from a nozzle test we did today

Isn't Your Life Worth More Than a Stupid Candy Bar Wrapper?

When you choose a nozzle, many factors go into this critical decision, or at least they should.

One major manufacturer of nozzles offers an option to prevent debris from fouling their automatic nozzle tips.  The screen that they offer, is typically found at the nozzle inlet, behind the bale.  In the break-apart models it is located at the inlet of the fog tip, ahead of the bale.  the screen prevents larger debris that cannot be passed through the nozzle on the flush setting from fouling the nozzle.  Theres a catch though....we have vandals on the prowl....



this kid has too much free time, so he thinks it would be funny to stick a candy bar wrapper in the standpipe outlet.  Here, we use the gated wye attached to a flow tube, it serves the purpose just as well.



The water flows, at 162 GPM.  A nice stream forms at the nozzle, if you bleed your nozzle too quick, you'll never know whats about to happen as you step over the threshold of the door to the fire floor.

...and then, boom, catastrophic failure of the stream.  This is from, a stupid candy bar wrapper....that's it.

The nozzleman is armed with a breakapart automatic nozzle, the smooth bore slug tip is 15/16"  He is quick to see the potential issue and you see the result above.

Is this possibility realistic?  You tell me?

Another test shows that trying the flush doesn't have any effect.

Don't die for a candy bar wrapper, buy the right equipment and know how the equipment you have works.  This nozzle works very well, if you use it properly in the right applications.

Thanks to the Richmond, Virginia Fire Department for planting the seed that led to this experiment.  Oddly, our nozzleman just happens to be wearing one of their hats!

Standpipes and Gated Wyes

Today, we conducted a brief experiment to determine the pressure loss in a 2 1/2" x 1 1/2" gated wye when the use of 2 1/2" hose is desired. A 20' section of 2 1/2" hose was attached to the flow tube on the fire hydrant. We used adapters in place of a bushing on the outlet of the wye with the following results;

With gated wye. 1 1/8" tip, 250 GPM. The flow was verified with a flow meter and handheld pitot gauge. Pressure at hydrant was 83 PSI. Tip pressure 50 PSI. Pressure loss was 33 PSI

Without gated wye. Same tip, same flow. Pressure at hydrant was between 48 and 50 PSI with corresponding tip pressure readings, meaning the pressure loss was negligible without the wye.

Assume a loss of 25 to 30 PSI through the valve with a setup like this. As you can see, the old 10 PSI loss is a big underestimate here.