Nozzles, flow-rates, pressures, techniques…etc! Guys help me - TopicsExpress



          

Nozzles, flow-rates, pressures, techniques…etc! Guys help me out. I made a lot of effort over the last years to establish for myself a “system” of teaching of the application of firefighting streams. I use the word system, because it includes a lot of different elements apart from of course nozzle techniques. I combine knowledge on hydraulics (flow capacities of hoses of different diameters, interactions between pressures and flow rates in hoselines and on tip of a nozzle, some pumping basics), required flow-rates for different applications, types and abilities of different nozzles and types and abilities of different streams (efficiency, reach, area coverage, cooing capacity, pressures of application), techniques (pulsing, pencilling, painting, jet stream application - while moving or in place). All this is put into the context of a building - type, size, height construction etc. I keep on telling my students This is my nozzle. There are many like it, but this one is mine... and they fortunately tend to see sense it it. But every now and then we have a discussion about water application and often times we read about more & different methods and techniques of application. It is enough to compare nozzle techniques (and nozzle types, pressures and flow rates) in Europe (a generalization) and in the US (another generalization). It is almost always about fog nozzle with rather lower rates and higher pressures and several techniques vs smooth bore with rather higher rates, lower pressures and seemingly fewer techniques. So my question is this. We all say and agree we have diferent tools in the toolbox, but dpo we? I do njot have a smooth bore im my toolbox. It does ride on my engine, but we would never use it in a structure fire. Why? Well, let me tell you. The models that we have are ball valve smooth bore nozzles and their parameters of work are 52mm Storz coupling (52 is standard interior line over here), it flows app. 200 lpm a 5 bar and 330 at 12 bar (but we dont use 12 bar lol not to mention 12 bar at the pump does not equal to 12 bar at the tip, and sometimes it is a huge difference, big time!). Ok, so we can take another tip (larger diameter) but it is not like they are sold in a set, advertised etc so to consciously get a nozzle that flows more requires some effort. This in turn means that almost nobody will do it and instead will get the standard version (I believe this is a 12mm diameter tip). No questions asked. Thus, nobody teaches smooth bore for interior use use, apart from maybe very few people. Or maybe even one person lol.. So what I am trying to establish is this. Apart from the European standard 6-7 bar at the tip and usually 100-500lpm on a nozzle with the ability to apply a straight stream and a spray at various angles (including the umbrella or shield), what are your choices? When, how and why would you use a smooth bore for interior operations? At what parameters (pump and tip pressure, flowrate, hose diameter). Also, recently I read about fog nozzles applying fog at 3 bar at the tip, how does that work? Again, what model, hoseline size, flowrate? Guys, I know may of you may not have time to even read though this carefully and I respect that. I even restrain myself from tagging people who I know would give me good answers. Please note that I took time to write all this and I was supposed to post it 2 days ago, but I wanted my description top be detailed and clear. Please do the same and if you only have time to write a sentence or two that will only cause more questions - please send the link to or tag someone that can give an answer and discuss a bit. Why? Because we have started this debate so many times and still, I didnt see any substantial outcome... RESPECT! Sz.
Posted on: Thu, 18 Dec 2014 10:00:52 +0000

Trending Topics



Recently Viewed Topics




© 2015