1. #1
    MembersZone Subscriber
    SamsonFCDES's Avatar
    Join Date
    Jul 2003
    Posts
    1,708

    Default Water Vs. Foam Vs. CAFS

    I have seen the claims that faom is 2x as effective as plain water and that CAFS is 2x effective as foam.

    Extinquishing power:

    1 gallon of water=1 gallon of water

    1 gallon of faom= 2 gallon of water

    1 gallon of CAFS= 4 gallon of water or 2 gallon of foam

    From your experience would you say this is an accurate estimation?

    I can see why in theory/scientificaly this may be so but I still would like to hear your opinions.
    -Brotherhood: I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve.
    -Mistakes: It could be that the purpose of you life is to serve as a warning to others.

    -Adversity: That which does not kill me postpones the inevitable.

    -Despair: Its always darkest before it goes Pitch Black.

  2. #2
    dazed and confused
    Resq14's Avatar
    Join Date
    Dec 2000
    Location
    New England
    Posts
    1,993

    Default

    "Extinguishing power" is kind of vague. After using CAF for a while now, there is little doubt it my mind that it is better than plain water, as well as regular, injected class A foam. If you want to say 4 times better, I'll believe it.

    It's easier to say that CAFS expands the volume of solution you have... and for this a factor of 4 would be conservative. You can stretch your volume 12+ times the same quantity of water. For interior structural attack that's probably a little on the dry side though.

    It makes the GPMs you are applying meaningful because the water isn't running out the door or into the basement. I agree with the big-wigs that say conventional fire flows in GPMs aren't necessarily the same with CAFS. Of course, some also disagree.

    You still need to make a dent in the tetrahedron. Whether you're absorbing BTU's, smothering, eliminating fuel (protecting interior and exterior exposures), etc... I think CAF wins each time for class A fires. I have little experience with class B fires so I can't comment on its effectiveness there. I've heard mixed results (and I'm talking LARGE class B fires, not just small gas leaks where even class A CAF will work)

    And of course, this is one of only many benefits. Bubble structure, light hoses, casting distance, negligable friction loss... there are many many benefits. Of course, there are potential drawbacks... cost and complicated systems being my top 2, but they're improving every year. We've discussed this recently in Apparatus Innovation under the "spec'ing a quint" thread or (or something close to that).
    Last edited by Resq14; 08-17-2004 at 03:35 AM.
    God Bless America!Remember all have given some, but some have given all.
    Google Is Your Friend™Helpful forum tip - a "must see" if you're new here
    Click this to search FH Forums!

  3. #3
    Forum Member
    VinnieB's Avatar
    Join Date
    Mar 2004
    Location
    On the couch in my skivvies
    Posts
    2,316

    Default

    Ok....I'll take the bait on this one.... especially after being coined "a big water fan"...or something like that... ....

    CAF, Water, Class A foam etc...its all good stuff...and as stated, depends how and what you are applying it to, water supply, and manpower availability....to name a few. Scientificly the results can't be argueed...too much that is . The "quint spec" thread in Apparatus Inovations details all this. As for experieance.....well here is mine...

    We use dacron dbl jacketed hose with smoothbores and 15/16" oriface. Our flows are 180gpm @ 50psi for 1.75", and 225gpm @50psi w/ 2.5"....our fire go out quickley. We average about 6 firefighters (our own) for a mid day house fire and our entire response area is hydrants. We use NO preconnects and stretch from the back step using a back stretch method. (oh boy..how archaic huh?...its amazing how fires ever went out? )....We get in and with the penetration from the line we get great knockdown and exinguishment using the BASIC principles of firefighting...Most of our fires are in apartment buildings and we never had a problem with water running out the front door...Surface tension is not a problem as long as you do proper overhaul. For this we place the OST on the nozzle...it's a 40gpm Outer Stream Tip for overhaul....and again...no problems...Using this method of attack..we average about 500gallons of water used for operations. We contribute this success because of proper and timed ventilation, aggressive interior attack, and good training.

    On the other hand...the old department I was from didn't have hydrants and brought appox 4000 gallons of water with positive results. We DID use "Cold Fire" in our water cans and Brush unit because for the Exact reasons stated earlier...Surface Tension...We were able to put the water/cold fire solution onto brush/wildland fires and not have to worry about flare up....It worked great!....

    For Class B fires...yes the Class A's will have limited success at small fires unless it is a Alcohol based substance buring...then its just like adding straight water. But as far as a Vapor Suppressor..Class A foam is useless...That's when you need the Class B foam and one of those "Pro-Paks"....especially with alcohol based products. I suggest the Universal Gold AR-AFFF. It can be used for A and B fires. When I attended Foam Tech School from IFSTA I was made a believer in this stuff.

    What I have been trying to do is get our Commishes to approve the purchase of Class A concentrates so i can just dump them into the tanks for that little edge that they provide. We have 300 gallons of bulk foam plus another 50 gallons of Baricade (awesome stuff!). But for 99% of the time we use straight water.
    IACOJ Member

  4. #4
    MembersZone Subscriber
    Dickey's Avatar
    Join Date
    Feb 2000
    Location
    Wisconsin
    Posts
    5,112

    Default

    Ok, I'll bite too. I hope this doesn't get to be a battle like other posts but here goes.

    We have had CAFS for about 9 years now. We have learned by lots of training and experiementing and have come to this conclusion. CAFS does not have the knockdown power or cooling power as plain water because it is "drier" than water. CAFS is excellent for everything but initial knockdown. SO........

    We use plain water for intial knockdown and switch to CAFS afterwards. It works so much better for overhaul and has great penetration. It works awesome for exposure protection as well, not to mention wildland firefighting. To sum it up, CAFS is great for all kinds of things and works awesome except for initial interior fire attack.

    Please don't bite my head off too bad.

    Keep your head down and your powder dry.
    _________________________
    Lt.Jason Knecht
    Altoona Fire Rescue
    Altoona, WI

  5. #5
    Forum Member
    1835Wayne's Avatar
    Join Date
    Feb 2002
    Location
    Door Village, IN
    Posts
    1,128

    Default

    Having bit, here is your argument.

    My department has a newer CAFS unit, (a year in service) and we use it extensively. The last sizable fire we had, it knocked down the main body of fire in no time flat. Can't give you a number ,I was kinda busy , but it was FAST. We run it pretty wet on initial attack and then dry it out later so we can get the BTU's ate up.

    We have not noticed a negative effect on initial attacks, but we do start out pretty wet on it.
    I.A.C.O.J. Charter Member
    "Chet, get an inch and a half on that!"

    "Not for fame or reward,Not for place or rank. Not lured by ambition or goaded by necessity. But in simple obedience to duty as they understood it. These men suffered,sacrificed,dared all, and died. Let us never forget our fallen friends."

  6. #6
    dazed and confused
    Resq14's Avatar
    Join Date
    Dec 2000
    Location
    New England
    Posts
    1,993

    Default

    Originally posted by Dickey

    We use plain water for intial knockdown and switch to CAFS afterwards. It works so much better for overhaul and has great penetration. It works awesome for exposure protection as well, not to mention wildland firefighting. To sum it up, CAFS is great for all kinds of things and works awesome except for initial interior fire attack.

    Please don't bite my head off too bad.

    Keep your head down and your powder dry.
    Hmmm, we've have had no problem with interior attack with CAF. If you're using "dry" foam then I can see this being a problem. We typically flow 70ish gpms water : 45ish cfms air. It's not shaving cream foam, more like bubbley class A. I agree you want wetter foam inside

    Not biting heads off, just sharing our experience as well.
    God Bless America!Remember all have given some, but some have given all.
    Google Is Your Friend™Helpful forum tip - a "must see" if you're new here
    Click this to search FH Forums!

  7. #7
    Forum Member
    VinnieB's Avatar
    Join Date
    Mar 2004
    Location
    On the couch in my skivvies
    Posts
    2,316

    Default

    Originally posted by Resq14
    We typically flow 70ish gpms water : 45ish cfms air. It's not shaving cream foam, more like bubbley class A.


    Well...there in lays another debate? How many lengths do you stretch?, What is your target flow? What type of nozzle?, What psi is the pump at?. I have another question...what is you response area demographics?.....I like to ask alot of questions...!



    Not biting heads off, just sharing our experience as well.
    I would agree.
    IACOJ Member

  8. #8
    Forum Member
    Rescue101's Avatar
    Join Date
    Jun 2001
    Location
    Bridgton,Me USA
    Posts
    8,162

    Default

    "Cafs doesn't work well for initial knockdown". Bull****! It doesn't if your operator doesn't know how to run it.And it requires a learning curve.ALL Cafs units are adjustable depending on what you want coming out the end of the pipe.More air/drier product less air more solution/wetter product.For intial attack keep it wet and nasty,you WILL achieve knockdown and quickly.Then dry it up a bit to finish it off.These systems work best if you have dedicated operators who know what to dial in when for a given situation.They are NOT rookie friendly.It took me two sessions before I got a handle on how to make the Cafs "play".And I've been running/teaching pumps for a long time.Pressures as Vinnie indicated are critical as to hose length for proper product delivery.The unit I'm used to works real well with 200' hose lengths.Do I think Cafs is the endall for fire suppression?No,but it's a real nice tool that can/does save labor and effort.And that's a wonderful thing. T.C.

  9. #9
    Forum Member

    Join Date
    May 2004
    Location
    Eastern Central Kansas
    Posts
    845

    Question

    Speaking of learning. Can someone explain the basic principles behind cafs and what it is and what it does. It would be greatly appreciated.
    FF I
    FF II
    Hazmat Operations
    EMT-B
    ---------------------------------------------------

    The light at the end of the tunnel has been temporarly shut off due to the current work load. The Mangement

    When all else fails USE DUCT-TAPE!!!

    My views posted in this fourm are my personal views only and do not reflect on any agencies that I am afiliated with.

  10. #10
    dazed and confused
    Resq14's Avatar
    Join Date
    Dec 2000
    Location
    New England
    Posts
    1,993

    Default

    Originally posted by VinnieB


    Well...there in lays another debate? How many lengths do you stretch?, What is your target flow? What type of nozzle?, What psi is the pump at?. I have another question...what is you response area demographics?.....I like to ask alot of questions...!
    [/B]
    The more questions the better!

    Lengths? 200' 1.75" lines are pretty common... and yep, they're preconnects. We also have a 250' 2.5" preconnected with a Blitzfire, 200' 2.5" preconnected off the back. These are all CAF-cabable, as is the deckgun. We also have a straight water 200' 2.5" off the back, and a non-preconnected 100' 1.75" in the bumper. We carry minimal spare hose, which is a known problem we are trying to fix. Preconnects are pretty standard in this area.

    As for target flow, I'm not sure what you mean. If you mean the computing fire flow for target hazards, I maintain that CAF and water are apples and oranges. Sure, if you flow the same amount of gpm's with CAF as you would with water, the fire would go out even faster. But that does not take into account the water that isn't actually doing anything... you're dumping tons of water a minute for a fraction of it to make a difference. IMHO (which is supported by some "pros" and disputed by others) CAF makes the gpm's that you are applying more effective because they're not in the street, yard, or floors below. And for departments that rely on the water they bring with them on wheels, this can make a huge difference.

    For compressed air foam, smoothbore nozzles work best. This is what we use, and I believe we have the 15/16" tip on at this time. Smaller tips = wetter foam, larger=drier. CAF is a finished product before it reaches the end of the hose. Thus "shapers" and all the little trinkets that are around are not needed. You can discharge it through the end of a hose, though your casting distance and ability to control it would be a little reduced. CAF likes friction... movement of CAF through a hose actually helps to mix and churn the solution with air. This is why systems typically specifiy a minimym length of hose to use based on diameter (smaller=shorter, larger=longer). It's usually 100' or so. You can use less, but the quality won't be as good.

    Pump pressure is standard at around 100psi. Whether we have 200' off, or 1400 feet of forestry line off... it's still 100psi. There is essentially no friction loss with compressed air foam It GREATLY simplifies operations once you get it up and running. Some configurations (especially newer ones) are far more user-friendly than ours. But it does work, and it works very well.

    The area is largely rural residential. We have a commercial district, and a touch of industy with some light manufacturing and a large oil-fired power plant. You'll also find Interstate 95 (now 295), Route 1, several rail lines, 5 islands (3 of which are accessible by boat only), two rivers, businesses, restaraunts, several nursing homes, daycares, and public and private schools. We only have 8300ish people to our name in 13ish square miles. So, we're obviously on the small side.

    I realize that life hazards and the potential for conflagration are far greater in areas more urban than mine. But our fires do go out without making swimming pools/parking lots/etc. And they go out fast, often with minimal staffing. Do we have a lot to improve on? You bet. CAF definetly helps us though.

    As for the low-down on compressed air foam and CAF systems, search around the forums here. There are tons of threads with some really good info by people farm more intelligant than I. Briefly, it's a typical around the pump foam system (FoamPro, etc). In addition, a large compressor injects air at each discharge. This expands the volume of the foam solution by adding bubbles of air. It can vary from just a little bit thicker than normal class A solution... ...all the way to as thick as shaving cream. You get better hang time for the solution, better insulating properties, better ability to absorb heat, penetration of class A, lighter hoses, stretches limited water supplies, negligible friction loss, and I've probably forgotten some more.

    Big drawbacks IMHO include price (up front and operational, for foam), system complexity, and maintenance. But if you can do it, I think it's worth it.
    Last edited by Resq14; 08-19-2004 at 04:58 AM.
    God Bless America!Remember all have given some, but some have given all.
    Google Is Your Friend™Helpful forum tip - a "must see" if you're new here
    Click this to search FH Forums!

  11. #11
    Forum Member
    Fire304's Avatar
    Join Date
    Jun 2002
    Location
    At the Helm
    Posts
    1,174

    Default

    Originally posted by VinnieB
    we average about 500gallons of water used for operations
    In our last live burn we averaged 40 gallons for room and contents knock down and another 10-20 for overhaul (usually too busy at a real fire to check water amounts). Almost no water damage outside of fire room. When I pump I usually go for 2:1 (70gpm/35cfm) on attack and 1:1 (30/30) on overhaul.

    Pull up to a house where you think it'll be a long pull? Hook up the 200' preconnect to the 200' dead lay, no need to worry about friction loss as there is none. I have pumped over 1000 feet at a brush fire.

    Dragging a CAFS line around is much easier than a charged water line (about 1/3 the weight). Kinks don't effect it unless really severe. A stair case in an old farm house that is a real struggle with water is just hard work with CAFS line.

    CAFS tends to "scrub" carbon out of the air and greatly improves visibility inside a smokey fire. Just watch the plume of smoke, it goes from grey/black to nearly clear within a few seconds of the nozzle opening up, it really is like magic and I would not have believed it is I didn't see it with my own eyes.

    Pump pressure is 100psi, nozzle pressure is pretty close to that.

    On the down side I've found is that its nearly impossible to communicate verbally while flowing CAFS, the nozzle is very noisy.

    Also, the truck does not like to run off hydrant pressure when pumping CAFS, you need the RPM's to generate a good supply of air. Our new CAFS brush truck does not even allow for running off hydrant pressure, you direct fill the tank or you run a draft.

    It takes a lot more pump operator skill to provide good CAFS to the attack crew on our large pumper, but it is possible to make a very simple CAFS pump as our brush truck demonstrates (and our next truck will follow that lead).

    Lastly, its expensive, both to buy and to operate (Class A foam to train with primarily)

    Is CAFS for everyone? No, if you have a hydrant every 300 feet and 50 FF's on your 1st alarm with an average response time of less than 5 minutes then no, you can overwhelm a fire extremely quickly.

    But if you are a rural FD with long response time, little in the way of water, or low manpower levels CAFS is a real force multiplier and I'd strongly recommend it.

    Got CAFS?
    ________________________________________________
    If you are new to posting please CLICK HERE for an essential lesson
    ________________________________________________
    A bad day in the boat is better than a good day in the office. And in my case the office is a boat!

    IACOJ Fire Boat 1

  12. #12
    Forum Member

    Join Date
    Feb 2004
    Location
    California
    Posts
    584

    Default

    I don't have much experience with CAFS but I am a big fan of Class A foam.

    I read a study several years ago done by Los Angeles County Fire. It found the use of foam greatly improved the effectiveness of the water application, it also found Class A foam systems to be 80-90% as effective as CAFS.

    Based on this I have never been very interested in CAFS for the following reasons.

    CAFS is several times the price of a good Class A foam system.

    CAFS is more complicated (more to go wrong).

    CAFS requires more training to use. Class A foam systems are simple to use and there is no way improper use of Class A foam can hamper firefighting efforts (even running it at 6% is unlikely to hinder firefighting, just make it messy). I know of a department that lost a building across the street from the fire station because the engineer was unfamiliar with the new CAFS system on the engine and it took several minutes to get effective water on the fire, those involved I talked to thought they would have saved the building with their old engine and plain water. Granted it was a training issue but sme department have enough trouble keeping their drivers competant with pumping as it is.

    So basically if money wasn't an issue, I had all the time to train that I wanted and could keep my firefighters focused on pump operations (so many firefighters eyes just glaze over during discussions about hydraulics, friction loss etc) then I would be all for CAFS but since I've never worked any place that had this situation (or even 2 out of 3) until I do I'll stick with Class A foam.

    As far as foam use in general, Class A foam, CAFS and even additives like wetwater you dump in the tank work by breaking the surface tension of water, so instaed of beading up and rolling off of materials the water clings and soaks in. The use of foam is very noticable during mop up.
    Class A foam and CAFS can also make thick foam blankets which is supposed to help hold water onto vertical surfaces (walls) which is kind of handy for protecting exposures or stopping a wildland fire although it is a fairly short lived effect (but longer than plain water) basically don't plan on just foaming a house and moving on in an interface fire or for exposure protection, it will need constant attention just less than plain water would.
    One thing CAFS is supposed to be able to do that Class A foam cannot is create very light fluffy foam which supposedly can be used to fill hard to reach places like attics and ceilings with foam (water)like the old high expansion foam generators although I don't know how useful this really is (anyone try this?)
    Last edited by NonSurfinCaFF; 08-21-2004 at 05:12 AM.

  13. #13
    Forum Member
    Fire304's Avatar
    Join Date
    Jun 2002
    Location
    At the Helm
    Posts
    1,174

    Default

    Originally posted by NonSurfinCaFF
    found Class A foam systems to be 80-90% as effective as CAFS.
    If you were using asperated nozzles or a Vindicator maybe, but we've been using Class A for over 20 years (my FD is extremely progressive) and CAFS blows away straight Class A.
    CAFS is several times the price of a good Class A foam system.
    If you are just looking at the price of the pump I'd say it's probably 50-80% more. When you factor in the whole cost of the apparatus its probably a lot lower percentage than that, Resq14 do you have those numbers?
    CAFS is more complicated (more to go wrong)
    This true but its also largely a function of design. Our big rescue pumper (2000gpm/250cfm) is very complicated and we've run into problems of not getting a timely supply of water on minor calls (we won't let an inexperianced operator pump on an interior call). But our new mini-pumper is so simple operator training takes about 15 minute. "Start pump, throttle up to max, engage compressor, pull discharge lever." Our next large pumper will be set up in the same way. You loose some of the ability to really fine tune the foam output, but the ease of pumping greatly makes up for that.
    Granted it was a training issue
    CAFS is different. We got our primary training from an Arizona FF who stressed that if you use CAFS like water it won't work. You must apply CAFS in a mannor most straight water guys would probably think of as "wrong" (basically you paint the ceiling and walls before you put a drop on the seat of the fire). He also stressed that it is not a magic bullet. You still need to be concerned about fire flow and on big fires you will still need big water. If you try to use CAFS on a defensive operation (the very first time we used CAFS we did this) you will do nothing but burn up thousands of dollars of Class A foam (which we did). The CAFS did a tremendous job of knocking the periphery fire down but there was no way to reach the seat and eventually it just burned through our CAFS.
    like the old high expansion foam generators although I don't know how useful this really is (anyone try this?)
    You can't quite get to the high expansion stuff, but you can make shaving cream. We've used it in void spaces and places we just didn't want to venture into. Its also extremely effective on wildland fires, you can make a very effective fire block that you can see. You can spray the side of a building and paint it white and the foam lasts a very long time. We burned a garage off a cedar shake sided house once, to within 2 feet of the house with almost no damage to the shakes (it was a training building we burned down in 3 stages). Even if you don't use it a lot, its a tool in the box for when you need it. In a ballon frame house you could really do a job stopping a fire behind the wall while another crew was looking for the source. If you had a vehicle with some hazardous contents inside you could stand back 50' and fill the compartment right up to the window sills with less than 100 gals of water use. Limited only by your imagination!

    Resq14 next time we do CAFS training we should try filling that 275 oil drum with CAFS to see how much water it actually takes.
    ________________________________________________
    If you are new to posting please CLICK HERE for an essential lesson
    ________________________________________________
    A bad day in the boat is better than a good day in the office. And in my case the office is a boat!

    IACOJ Fire Boat 1

  14. #14
    dazed and confused
    Resq14's Avatar
    Join Date
    Dec 2000
    Location
    New England
    Posts
    1,993

    Default

    Originally posted by Fire304
    If you try to use CAFS on a defensive operation (the very first time we used CAFS we did this) you will do nothing but burn up thousands of dollars of Class A foam (which we did). The CAFS did a tremendous job of knocking the periphery fire down but there was no way to reach the seat and eventually it just burned through our CAFS
    We went through a great deal of foam because a bypass valve had been opened while the FoamPro was being serviced, and it had not been closed. Thus our foam was being "injected" (dumped) at a ridiculously high percentage... haha 20%+? I was dumping in buckets of foam before realizing something was not right, and comparing gallons of water flowed with gallons of foam used.

    There was nothing to be saved at that fire anyway... fire had extended through most of the "barn" before we were on scene. It was definetely a defensive "protect the exposures" and "cool the thermal column." So it probably was not worthwhile to waste any foam on it any how.
    God Bless America!Remember all have given some, but some have given all.
    Google Is Your Friend™Helpful forum tip - a "must see" if you're new here
    Click this to search FH Forums!

  15. #15
    MembersZone Subscriber

    Join Date
    Aug 2004
    Posts
    55

    Default

    This is all great info guys. My department just got out first 4 cafs pumps and the guys seem to have alot of questions. One study I saw from New Zealand said that average fire hose may not be cafs compatible. Any one have any thoughts? Thanks.

  16. #16
    dazed and confused
    Resq14's Avatar
    Join Date
    Dec 2000
    Location
    New England
    Posts
    1,993

    Default

    We use our normal fire hose.

    Some opt for Reeltex lines made by Niedner. Kind of a combination "real line" with a booster line as it is hard to collapse.
    God Bless America!Remember all have given some, but some have given all.
    Google Is Your Friend™Helpful forum tip - a "must see" if you're new here
    Click this to search FH Forums!

  17. #17
    Forum Member

    Join Date
    Sep 2004
    Location
    metro detroit
    Posts
    85

    Default

    We've been using straight class A for 4 years now and have been impressed with it's knockdown ability. We won't be specing a new truck anytime soon and hopefully the price of cafs will come way down in 5-8 years. It was hard enough to get some of our guys to accept using class A let alone changing things operationally with a caf system. I agree that class A has at a minimum a 2x effectiveness of water. I would estimate a 3-4x effectiveness. We found that after knockdown of a bedroom for example, we would open dresser drawers and find these spaces filled with foam. The foam was "checking for extension" ( and taking care of it) before we were able to. I can't figure out why fire chiefs are still specing fire trucks without these systems on them.

  18. #18
    Forum Member
    Fire304's Avatar
    Join Date
    Jun 2002
    Location
    At the Helm
    Posts
    1,174

    Default

    Originally posted by engineeremtp
    I can't figure out why fire chiefs are still specing fire trucks without these systems on them.
    $$$ and fear of using something that is unknown.

    I'm not saying its right, its just reality.
    ________________________________________________
    If you are new to posting please CLICK HERE for an essential lesson
    ________________________________________________
    A bad day in the boat is better than a good day in the office. And in my case the office is a boat!

    IACOJ Fire Boat 1

  19. #19
    MembersZone Subscriber
    FirefighterLong's Avatar
    Join Date
    Apr 2004
    Posts
    27

    Lightbulb Sprinklers/Standpipes??

    Great information everyone.

    We just ordered two new Engines with CAFS systems so I'm excited to see the difference. One question I had was with stand pipes and sprinkler systems. We typically pump sprinkler systems at 150psi to the FDC plus friction loss per floor. Stand pipes are calculated at 125psi for our high rise pack plus friction loss to the FDC and height. How would you pump to these using the CAFS system?

    Thanks

    FFLong
    Proud Volunteer Firefighter!

  20. #20
    Forum Member
    Fire304's Avatar
    Join Date
    Jun 2002
    Location
    At the Helm
    Posts
    1,174

    Default

    Excellent question and I don't think anyone knows the answer as if its been done its not been widely published.

    If I pulled up to an FDC with a CAFS truck, unless I had a massive fire that was overwhelming the sprinkler system I would hesitate to put anything more than water into the pipe. The sprinklers should be designed to be very effective with water provided that the system has not been modified or tampered with. Adding Class A may boost its effectiveness, but if it were designed to be 110% to begin with whats the use? If the decision was made to use CAFS I'd want to be sure the PIV was closed first so I didn't have to worry about contaminating the drinking water for the town and not have my CAFS watered down if the incoming pressure was close to 100psi.

    Points ot ponder...
    If you put foam in the sprinkler system you might have a very unhappy owner as the entire system will probably have to be flushed.

    Mixing CAFS or even Class A with the existing water in the pipes will greatly reduce the effectiveness of the foam until the water is blown out.

    If the check valves leak by you'll be contaminating the public water supply with your foam.

    Is the sprikler head a type that works well with CAFS or Class A, or does it actually reduce the effectiveness of the head to run anything other than water through it (might not reach as far or cover as even).

    Friction loss does not exist with CAFS, you set the pump to 100psi and forget it, so both sprinklers and standpipes are much easier to pump. I don't know if you need to calculate elevation loss with CAFS (not something we have to worry about here) if you go up high enough you might need to boast pressure a little.

    CAFS in standpipes would be awsome, would not hesitate to do that.
    ________________________________________________
    If you are new to posting please CLICK HERE for an essential lesson
    ________________________________________________
    A bad day in the boat is better than a good day in the office. And in my case the office is a boat!

    IACOJ Fire Boat 1

  21. #21
    MembersZone Subscriber
    FirefighterLong's Avatar
    Join Date
    Apr 2004
    Posts
    27

    Smile Good Points

    Fire304,

    Good Points about contaminating the public water supply and filling the sprinkler system with foam. I'm sure the cost would sooner or later come back to us. We have lots to learn about the CAFS.

    FFLong
    Proud Volunteer Firefighter!

  22. #22
    dazed and confused
    Resq14's Avatar
    Join Date
    Dec 2000
    Location
    New England
    Posts
    1,993

    Default

    Originally posted by Fire304
    I don't know if you need to calculate elevation loss with CAFS (not something we have to worry about here) if you go up high enough you might need to boast pressure a little.

    CAFS in standpipes would be awsome, would not hesitate to do that.
    "because the foam contains air, it is muchlighter than the same volume of water and can be pumped to twice the elevation under the same pressure -- an important point in high-rise building fires and when supplying elevated streams"

    pneumax
    God Bless America!Remember all have given some, but some have given all.
    Google Is Your Friend™Helpful forum tip - a "must see" if you're new here
    Click this to search FH Forums!

  23. #23
    MembersZone Subscriber
    FirefighterLong's Avatar
    Join Date
    Apr 2004
    Posts
    27

    Smile

    That makes perfect sense. Thanks

    FFLong
    Proud Volunteer Firefighter!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Log in

Click here to log in or register