Printable View
I am familiar with 2 inch hose operations but with a vindicator nozzle. For those that have 2 inch hose or thinking about adding it, what type of nozzles do you have. Also what would your nozzle preference be on this hose line?
Fog Nozzle
Smooth Bore (what tip?)
Vindicator Nozzle
Thanks
We have 2" in our hi-rise packs, with compact 75psi TFT nozzles. We are thinking of switching to 2" for our attack lines as well. For these we would use our full size 100 psi TFT's.
Elkhart Chief 250 GPM @ 50 psi
Smoothbore with 1 1/8 and 1 inch tips.
Elkhart Chief Breakapart nozzles. 1 1/8" Smoothbore, 200GPM@75PSI fog tip. These are on our 200' crosslays. Our rear 300' preconnect and 200' highrise kit are plain 1 1/8" smoothbore nozzles.
We have three crosslays with 200 feet each of 2 1/2" line with adjustable fog nozzles.Red and yellow for attack lines,blue for when we have enough respond to also form a dedicated RIT team.
Our engines are capable of 1500 GPM but when a two man crew is attacking,the engineer keeps it down to 100 GPM @100 psi.
Nothing in district is over three stories so no highrise packs or even a ladder truck yet.Those days can and will come though.
Doughesson,
Are you sure they aren't your 1 3/4 lines. If you are flowing 100gpm @ 100psi off your 2 1/2 (or even 1 3/4 for that matter) you might want to look at increasing that. Many departments are using nozzles that flow 150-250gpm @50psi on their 1 3/4 lines. 2 1/2s should flow more than 250gpm @ 50psi. 100gpm is not a lot of knock down power.
You should look at your flow more carefully. It takes between 150-180 GPM on 1 3/4 to knockdown a fire.With the higher number being the best.A 2 1/2 is used for large bodies of fire hence the greater flow of 250 GPM.
My company has 200' feet of 2" hose with a fog nozzle. We don't use it much, we only run with an officer and 2 FF and it gets to be a little too much for one guy to handle comfortably in a building.
We have a 2" attack line on each engine. 2" with a Saberjet nozzle.
Spartan, how do you guys like the saberjet? we have 1 that was just put into service....mixed reviews so far ("a getting used to it" issue) PM me so we don't hijack the thread ;)
Personally I think 2" hose is pointless. My volly company uses 2" hose with 1 1/2 couplings. On the 2" we use TFT automatic Nozzles. The only real difference with the 2" compared to 1 3/4" is that the 2" is more difficult to maneuver. The difference in friction loss does not make much of a difference. Just stick to the 1 3/4 with a solid bore.
We use 2" 200' preconnect with an Elkhart SM30 automatic fog nozzle(300gpm capacity). IMHO this is the BEST line ever placed into service! Still has the manouverability of a hand-line but can flow 180-200 gpm. We use them for our 2 & 3 story apartments (wood frame) and can still get up stairs and around corners with limited crews.
2 inch line with a stack tip
vindicator...
We use 2 inch exclusively for handlines ops. They have an Elkhart 200 gpm at 75 psi break apart nozzle with a 1 1/4 inch slug tip. This has worked extremely well for us.
Firefiftyfive...
Not much difference in friction loss? Really? This holds true only if you are using the low friction los 1 3/4 inch hose wihich in reality is closer to 2 inch than 1 3/4 inch in inside diameter. The difference is quite dramatic if you are using real 1 3/4 inch hose versus real 2 inch hose.
let's do the math for a couple of flows...
180 gpm
Q = 1.8
C = 15.5 for 1 3/4 inch and 8 for 2 inch
FL = C(QxQ)
FL = 1 3/4 inch hose 15.5(3.24) = 48.6 FL/100 feet
FL = 2 inch hose 8(3.24) = 25.92 FL/100 feet
300 gpm
Q = 9
FL = 1 3/4 inch hose 15.5(9) = 139.5 FL/100 feet
FL = 2 inch hose 8(9) = 72 FL/100 feet
I know these are merely mathematical formulas...but if you are using real 1 3/4 inch hose and real 2 inch hose the fact that 2 inch hose has almost half the friction loss is not something to ignore.
At 300 gpm for 200 feet of hose your EP for 1 3/4 inch hose would have to be 280 plus the nozzle pressure. For 2 inch it is 144 plus the nozzle. Hmmmmm...with 2 inch you could still use yout TFT's, although I wonder why you would want to. We prefer the ease of lower pressure combination nozzles and the slug tip.
FyredUp
I’ve little experience working with 2”. However, if I did -- my nozzle preference would be smooth bore 1” or 1-1/8” for structural fire attack.
Couple of things I’d consider. (note: all Flow and FL's are approximations – I’m not a mathematician).
1-1/8” tip = 260gpm at 50psi – 2” line approx FL 27psi per length.
1” tip = 210gpm at 50psi – 2” line approx FL 14psi per length.
1-1/8” tip = 260gpm at 50psi – 2-1/2” line approx FL 7psi per length.
15/16” tip = 180gpm at 50 psi –1-3/4” line approx FL 25psi per length.
IMOP, flows above 260gpm on a handline can become pretty unmanageable for the average engine crew unless they’re sitting on it in front of a taxpayer.
You guys would have to tell me how the 2” line handles at approx 30psi FL per length flowing 260 gpm especially on long hand stretches up multiple stories (no stand pipe). Have you guys established any limits on the amt of lengths you’d stretch with a 2” hand line -- especially with a fog tip (similar to a 6 length rule of thumb for 1-3/4”)?
I’m a bit old school however, I do approach things with an open mind. Like I said, I’ve little experience operating 2” hand lines. I still believe in the 1-3/4” when 150 to 180gpm flows are required and 2-1/2” when flows above 200gpm are required. I guess 2” fits somewhere in between 210-220gpm flows but to me that’s splitting hairs.
Imop, if you need more than 260gpm flows get a second line with appropriate manpower. It’s a dangerous practice to pump the sh#$ out of a hand line to achieve the required flows as opposed to deploying additional hand lines with properly staffed engine crews. Nothing ****es me off more than when mfg’s offer products to the fire service under the auspices of doing more with less (reduced staffing i.e. quint concept).
Bottom line, if 2’ works for you that’s great! As long as some num-nutz isn’t proclaiming 2-1/2” flows with 1-3/4” manpower.
Safety = Properly Staffed Co’s with high quality equipment/tools/apparatus -- reliable, fully evaluated/tested and well maintained.
Stay Safe.