Thread: Foam ops., 11/2 vs. 1 3/4 hose
07-04-2000, 02:11 PM #1FF13Firehouse.com Guest
Foam ops., 11/2 vs. 1 3/4 hose
Help! We use 1 1/2 hose with our 60 and 95 GPM eductors. The maximum anoumt of hose from the eductor to the nozzle is 350' for the 60, and 150' for the 95 GPM eductor.
My question is; How much more hose can be added from the eductor to the nozzle when using 1 3/4 instead of 1 1/2?
Anyone who can tell me where to find this information in print would be of great help. Thanks!
07-04-2000, 10:18 PM #2KEAFirehouse.com Guest
That depends on the MEASURED friction loss of your hose. Realize that just because someone puts it in print does not mean that you will see the same resulst on the fire ground. Most hose is tested on straight level ground of which few hose lays at a fire are straight on often not level.
The simplest solution for a longer hose lay from the eductor (MY OPINION, and you all have the right to disagree, it wont bother me!) is to use a low pressure noszle. Lowering the required nozzle pressure can provide you with a great deal more hose length for only a 60 or 95 gpm flow.
07-08-2000, 02:10 PM #3LHS'Firehouse.com Guest
...350' for the 60, and 150' for the 95 GPM eductor...
So at 60 gpm you'd be safe out ot 450 feet and ith 95 gpm 200 feet. The key with foam is to use a UL listed concentrate that has been tested with the UL listed for the UL listed nozzle and eductor you plan to use. Why, 3M is quite clear in their literature(they have 64% of the US maret and 80% of the world market) that some big name popular eductors in the 6% setting only educt 3.2% and at 3% pick up 2.2%. The maufacturer listed 200 psi EP in reality 300 psi was needed to get 40 to 50% of what was listed on the eductor. So if you want to die at a fuel spill or fire use un listed nozzles, foam and eductors. If you don't have matching listing card, don't do it. Some hydrocarbons and polar solvents have flash rates in excess of 120 to 80-0 feet per second, you won't get a second chance.
It isn't an issue of low pressure nozzles, that is beacuse mos foam nozzles are low pressure. ZThe difference in burnback resistance on afff is 5 to 7 econds or 5 to 15 minutes depaending upon the nozzle you use.
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