Look here for a prior discussion:
I agree with Damon! The spring that is in the automatic nozzles produce a pretty stream, even at low pressures, which could lead an inexperienced pipeman to get a false sense that they are getting the proper gallonage. We use a break apart, constant gallonage nozzle with a fog tip and a 15/16 inch smooth bore. I prefer the smooth bore myself as it can be used at a lower pressure with better penetration than the fog.
I am glad this discussion came up, we have the TFT Automatic Fog Standard/Low pressure with breakaway tips to the 15/16 smooth bore on our 1 3/4"
The standard gives a nice stream no matter the gallonage.
The low pressure stream increases the gallonage by 50 GPM or more at the same pressure with less reach. I think the main idea of the low pressure fog is for high rise type scenarios when your pressure sucks and you still want at least 100 GPM flowing, which as I said, has less reach.
The 15/16 Smooth Bore of course gives you 185 GPM at 50 psi NP. The only problem is, the TFT 15/16 Break away smooth bore does not feel like a normal smooth bore. It is not an ideal smooth bore and does not flow like one. The hose is extremely awkward to handle. I have not experienced anything like this before except with these tips. A regular smooth bore tip is much better.
If you want a smooth bore, buy a real smooth bore. Not a breakaway tip.
You know what Gary. It is interesting you say that. The evidence can be further proven by the manufacturers peddling these low pressure fog nozzles the past couple years 150@50psi, etc. However what FD's did not consider was that by using older technology hose with newer low pressure nozzles they ended up having huge kinking issues.
Every nozzle can flow water...but the question is now; how can it be done simply and cost effectively? And I would have to lean too smoothies with only a few exceptions. I can't tell you how many times on the training ground or on a scene that I have seen inexperienced nozzlers fumble with a fog nozzle. It all boils down to training, experience and application.