1. #1
    bfd1071
    Firehouse.com Guest

    Post friction loss rule of thumb ?????

    Can anyone answer a question i have in regards to 1.75 hose and a friction loss rule of thumb.

    I have been told different "rule of thumb" friction loss for Angus hose. I know the more water the more friction loss. I have been told 25 per 100 feet total water flow of 180 gpm, then i have been told 40 per 100 feet. can anyone answer this for me?

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    ** The opionions are mine and mine alone, they are not that of my dept or the local**

  2. #2
    COFireLt
    Firehouse.com Guest

    Talking

    Your best bet would be to dig out the books and find a formula that's easiest for you, it seems like everyone has a way to figure it out. I use a cheat sheet with the FL already figured for all handline sizes and the same for relay pumping ect.... as for the gpm, we have standards as far as most uses. There are several books that will help determining the formula that works best for you. Fire Engineering has a couple editions on first service hydraulics, covering theory, water, practice, and foam. They are kinda older editions but very useful. Have fun!!

  3. #3
    Ward Watson
    Firehouse.com Guest

    Cool

    bfd1071,

    Remember that rule of thumb is a number derived from a master hydraulic calculation. In the IFSTA Fire Streams book, the formula for calculating friction loss is C x Q (squared)x L. Where Q is the coefficient of friction, which in the case of 1.75" hose is 15.5. Q is gallons per minute divided by 100. L is the length of hose divided by 100. You have chosen to use 180 gpm. Now lets put it all together.

    C x Q(squared)x L =

    C=15.5
    Q=180/100=1.8
    L=100/100=1

    15.5 x 1.8(squared)x 1 =
    15.5 x 3.24 x 1 = 50.22 psi fl

    Remember that rule of thumb is an approximation of a figure derived from a master hydraulic calculation.

    So in conclusion, we can safely say that a good rule of thumb for 1.75" hose flowing 180gpm is 50 psi per 100'

  4. #4
    LHS'
    Firehouse.com Guest

    Post

    Simplest formula is 1 gpm for every psi pump pressure on a 200 foot line. 150 psi 150 gpm, 200 psi 200 gpm, etc

  5. #5
    bfd1071
    Firehouse.com Guest

    Post

    Thanks for your replies

    ------------------
    ** The opionions are mine and mine alone, they are not that of my dept or the local**

  6. #6
    KEA
    Firehouse.com Guest

    Post

    bfd1071:
    Angus High Combat FL ?

    When you get told something by a manufacture or their representative please make them prove it to your satisfaction.

    A recent test in NY using BRAND NEW Angus High Combat hose supplied by the local vendor provided the following results.

    Note: The test was done with 100' of hose to establish the known FL for 100 feet.

    EP NP GPM FL
    140 60 278 80

    A recent test of 100-of Angus High Combat in New Mexico resulted in this set of numbers

    EP NP GPM FL
    160 60 360 100

    Add the friction loss to the EP for another 100 feet of hose and you can quickly tell that the 1-psi per 1-gpm idea would not work for this brand hose.


    To all:
    As far as using 1-psi per gpm desired on 200 feet of hose....Chew on these results and you decide if such a concept works for you.

    EP NP GPM FL 200'of hose
    145 100 99 45
    135 35 160 100

    These are results of a recent test done by a NY department. As you can see, the proposed concept of 1-psi per 1-gpm would have told you to pump 99-psi for a flow of 99-gpm on the first test. Unfortunatly that engine pressure would fall 45-psi short of what it actually took to get the 99-gpm.

    The second test using the proposed 1-psi per 1-gpm concept would give you an engine pressure of 160-psi....25-psi higher than needed to actually get the desired flow of 160-gpm.

    I personally do not care for rule of thumb numbers. The hose brands that are out there are too numerous and different for this idea to work proplery in my opinion.

    Build a pump chart by using a flowmeter placed on the intake of your rig and pull each line and test the flow. Once the desired flow is achieved simply record the EP it took to get it and now you KNOW what your flowing instead of guessing.

    Besides, do you want to be the one that sits on the witness stand one day after a LODD and tell the judge, "Our rule of thumb tells us that we were flowing 99-gpm", when in actuality you were pumping 45-psi short of what you thought you were gettting.

    Opinions, myths, ideas, etc..., they are useless without facts to back them up.

    TEST...TEST....TEST! KNOW what your flowing!

    This post is not intended to promote or degrade any person or product. It is simply my opinion backed with facts to support it.




    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  7. #7
    NUMBY
    Firehouse.com Guest

    Post

    We use mostly angus High Combat and we were switching some hose loads one day and wanted to test out calculations to see how accurate they were. What we noticed with the high combat was that at low pressures it has about the same friction loss as other cotton 1 3/4. But when we increased our pressure the friction loss actually went down. The only thing we could come up with is that the hose was actually expanding at higher pressures. I have heard from other people that at higer pressures the high combat will swell to almost 2". Hard to use any rule of thumb calculation. Best thing to do is get some flow meters and pressure gauges and go out and do lots of testing as we did.

    ------------------
    Anything left in the forums is my opinion and does not reflect my department or any organization i belong to.

  8. #8
    KEA
    Firehouse.com Guest

    Post

    Numby: You hit the nail on the head. FLOW meters don't lie if they are calibrated properly.

    If you want to have fun with the hose salesman try this:

    Take a blood pressure cuff and place it around a charged line at 75-psi. Bring the pressure up to around 175 and watch the gauge grow! The more the gauge moves, the more the hose expands under pressure.

    It takes the sales pitch out of one hose type trying to knock another by claiming one expands as the excuse for better FL numbers.

    I dont care if it expands as long as the inner liner is not glued to the inner jacket. If it is, the growth underpressure streaches the glue and evenutually it will delaminate.



    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  9. #9
    bfd1071
    Firehouse.com Guest

    Post

    You state to use a flow meter, where do you put it? We run 100 feet of 2.5 that goes down to the 1.75 line. I beleive it is about 300 feet total. They put the flow meter at the end of the 2.5 line. Would it be better to use a smooth bore and a pitot gauge? You do loose alot of gpm due to friction loss at the nozzle correct? Tell me what you think.

    ------------------
    ** The opionions are mine and mine alone, they are not that of my dept or the local**

  10. #10
    KEA
    Firehouse.com Guest

    Thumbs up

    bfd1071:
    "where do you put it?"

    I would recomend placing it on the intake. This permits you to pull any line (One at a time) and test the flow.

    What type of flowmeter do you have? You can use the smooth bore and pitot to calibrate it assuming its a flow meter that can be calibrated. If you can't calibrate it your flows may show one thing and actually be another.

    "They put the flow meter at the end of the 2.5 line."

    You can do this although depending on the type of flow meter you may find that your flows are different when you take the flowmeter out of the line. It shouldnt be that noticable although I have seen one off brand flowmeter that had VERY high FL and would definatly make a difference. I do not know the name of it, however I have not seen them at any shows since the IAFC show in St. Louis. I doubt your using that type of flowmeter.

    !!!!!Dont place a flow meter in line that the city water department uses. Those also have treturous FL and will definatly effect your flow numbers vs pump pressure when you take it out. (Your flows would be higher)

    "Would it be better to use a smooth bore and a pitot gauge?"

    If that is what you use on that line...YES. If not, use a flowmeter. The reason I say this is depending on the care you have given you nozzles over the years they may or may not flow what they are supposed to at a given nozzle pressure. This becomes more evident with automatics that have not been serviced regularly. (THIS IS NOT AN ATTACK ON AUTOMATIC NOZZLES)

    I say this because of a recent test done in Texas with 6 automatic nozzles of the same model, at the same discharge pressure, flowed between 162-232 gpm. Not one of them flowed the same and one would not regulate NP. These nozzles were on active engine companies, yet had never been serviced, even though the manufacutre tells them to.

    After testing a brand new one of the same brand, we did achive proper nozzle pressure according to the manufactures specifications.

    I want to emphasize that this is a service problem! When serivced properly 99% of the nozzles on the market work just fine. If you don't serivce them (Assuming your nozzle requires routine service) dont blame the manufactures...unless it makes you feel better.

    "You do loose alot of gpm due to friction loss at the nozzle correct?"

    Some nozzle do have a much lower exit pressure than inlet pressure. The difference is your FL in the nozzle.

    If your nozzle is flowing 200-gpm, the FL inside the nozzle could be a million psi, yet it is still flowing 200-gpm. What goes in, comes out.

    If 200-gpm comes out of the discharge, you will have 200-gpm come out the other end of the hose...you only loose pressure, not flow.

    Hope this helps!

    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  11. #11
    LHS'
    Firehouse.com Guest

    Post

    ""As far as using 1-psi per gpm desired on 200 feet of hose....Chew on these results and you decide if such a concept works for you. These are results of a recent test done by a NY department""

    Thats nice, I'll trust the UL label on the hose and the UL friction loss tests that came with the product. They test our ladders and don't sell hose or nozzles. UL says 250 gpm 59 psi on the hose we use. NP 100 60 plus 60 = 220 rule of thumb 250 psi. Close enough for me. Heck there just might be some line loss in the plumbing. 200 gpm according to UL 38 psi 100 plus 40 plus 40 176 psi, gosh I'm off by 24 psi, so what. In either case run a 250 foot line and be dead on.

    "". As you can see, the proposed concept of 1-psi per 1-gpm would have told you to pump 99-psi for a flow of 99-gpm on the first test. Unfortunatly that engine pressure would fall 45-psi short of what it actually took to get the 99-gpm.""

    Gee if you are really pumping 99 gpm with 1 3/4" hose you might ask why yu're not using 1" or 1 1/2" hose instead.

    UL 3.4 psi at 100 gpm. 3.4 x 2 = NP = 107 psi, off by 7 psi.

    After all he asked for friction loss rules of thumb. Why don't you offer one nozzle salesman.

    ""I personally do not care for rule of thumb numbers. The hose brands that are out there are too numerous and different for this idea to work proplery in my opinion.

    Build a pump chart by using a flowmeter placed on the intake of your rig and pull each line and test the flow. Once the desired flow is achieved simply record the EP it took to get it and now you KNOW what your flowing instead of guessing.""

    We have all the stuff you mention on each and every rig figured to lays to 9000 feet. It is from that that we put together our rules of thumb.

    YOu know 1 psi equals 1 gpm

    flow in hundreds divided by 2 equals FL in 5" hose, UL says 4.1 psi we say 5 at 1000 gpm.

    1" hose EP divided by 3 = gpm on a 150 line.

    gpm in hundreds times it self equals fl in 3" 4 x 4 = 16 psi FL UL says the same.


    <<Besides, do you want to be the one that sits on the witness stand one day after a LODD and tell the judge, "Our rule of thumb tells us that we were flowing 99-gpm", when in actuality you were pumping 45-psi short of what you thought you were gettting. >>

    Oh I'm sure that will happen, tell me where? We sit on seat belts, go into fully involved McDonalds that are vacant, send guys in vacant structures, don't wear masks, don't account for our people for 1 hour, say "we didn't know who was onscene" at fatal fires, don't follow fire codes, national standards, or ISO.... oh please give us a list of a few dozen folks getting sued over EPs and NPs or telling the judge squat. In some states, it is the judges who fund or don't fund the fire department.

    So I'm asking you to back up your statement "Opinions, myths, ideas, etc..., they are useless without facts to back them up. "

    So who's on the witness stand and where?

  12. #12
    Capt. Zada
    Firehouse.com Guest

    Post

    LHS;

    Your last post was very confusing as to what ideas you were presenting. Please explain them.

  13. #13
    KEA
    Firehouse.com Guest

    Post

    LHS:
    Larry I'm glad that your rule of thumb works for you. As you pointed out, you achieved your rule of thumb by building a pump chart.

    "Gee if you are really pumping 99 gpm with 1 3/4" hose you might ask why yu're not using 1" or 1 1/2" hose instead."

    I was not the one pumping these flows Larry so relax. I agree if that is all they were going to flow why have that size line. See Larry, we can agree on something. What a novel idea

    "gosh I'm off by 24 psi, so what"

    Well I think a 24 psi mistake could lead to a real problem if it ends up that your nozzle is getting 25-psi less than needed.

    A nozzle (NO BRAND NAME OR TYPE MENTIONED) that is rated at 212gpm @ 100-psi NP only flows 73-gpm at 75-psi NP. If you missed your target by 25-psi could you have 25-psi less nozzle pressure? If so, you lost 66% of your flow over a 25-psi mistake. If this doesn't bother you then fine.

    "Why don't you offer one nozzle salesman."

    I think my post made it clear why I do not promote a rule of thumb. I'm confident that the people reading the information posted are smart enough to figure out what to use and what not to use. My suggestion was clear, and even was confirmed by yourself as being a valid way to do it with your last post. Thanks Larry, we again found mutual ground to stand on

    "do you want to be the one that sits on the witness stand one day"

    "ONE DAY" Larry! I did not say that anyone was sitting on the witness stand but I must ask, are you of the opinion this cant or won't happen?

    I'm simply trying to promote sound principals to ensure people know what they are flowing. Nothing more Larry.

    I'm sorry if my post bothers you. That was not its intent.

    Have a nice Day




    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  14. #14
    KEA
    Firehouse.com Guest

    Post

    LHS:
    "UL says 250 gpm 59 psi on the hose we use."

    What brand of hose do you use? You say UL says... Are you stating that the hose you use is UL listed?



    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  15. #15
    LHS'
    Firehouse.com Guest

    Post

    <<Well I think a 24 psi mistake could lead to a real problem if it ends up that your nozzle is getting 25-psi less than needed.>>

    Dang a that would be a real trick pump 24 pounds less and the nozzle gets 25 psi less. I guess that goes along with your, “I'm simply trying to promote sound principals to ensure people know what they are flowing.” Concept. Modern math I guess. 250 gpm auto tip will maintain 100 psi NP with 24 psi less for flow. I’ll just have to scrape by on 230 gpm. I bet the fire will never know. I guess we could go to override and get the flow up to a mere 280 gpm. At 226 psi Ep with a fixed flow 250 gpm tip if I follow your hydraulics, if I pump 24 pounds less the nozzle will drop 25 psi and the friction loss won’t change. Guess what? It doesn’t work that way, at 75 psi the 250 tip flows 217 gpm. The FL would then drop too. Reality is a slightly lower EP equals a slightly lower gpm even 24 psi wouldn’t make squat for difference to the fire.

    <<A nozzle (NO BRAND NAME OR TYPE MENTIONED) that is rated at 212gpm @ 100-psi NP only flows 73-gpm at 75-psi NP.>>

    Another make flows 1000 gpm at 100 psi and only 300 gpm at 70 psi. And they’ve worked well for over 25 years. Dang if you missed the target by 30 psi you’d be off by 700 gpm.

    <Are you stating that the hose you use is UL listed?>

    Every length of it is labeled, and 1 in ten lengths is flow tested.

    <What brand of hose do you use?>

    2000 psi test 700 psi working pressure Mercedes Textile hose.

    <<are you of the opinion this cant or won't happen>>

    Sure when hell freezes over. Gee 25 psi is a killer, so why are relief valves allowed to have a 30 psi variation, pressure gauges a 6% high or low difference on a 600 psi face, guys with smooth bore tips can’t even get the relief valve to work at 60 to 95 psi pressures, plumbing on the cross lays is set for 200 gpm with 40 psi loss and 100 psi loss out the rear, nozzles you say have 25 psi losses in them, every make of flow has a different friction loss of as much as 100 psi at the same flow, flow meters round out flow to the nearest 10 gpm or so maybe???? and you are sniveling about 25 psi????? So where are all these fires that are not going out just fine with all the nozzles everyone is using? Start the class action suit to save all these guys lives.



  16. #16
    KEA
    Firehouse.com Guest

    Post

    LHS: Lets try this again. What brand of hose do you use?

    "Well I think a 24 psi mistake could lead to a real problem if it ends up that your nozzle is getting 25-psi less than needed."

    Note Larry that the post clearly states IF IT ENDS UP THAT YOUR NOZZLE IS GETTING 25-PSI LESS THAN NEEDED.

    Maybe I missed somehting but I normally add NP to my total EP. If my hose is eating up 25-psi more FL than I thought, then my nozzle MAY not be getting that extra 25-psi due to FL.

    I dont think that I mentioned anything about pumping less Larry. You did. Your correct that if you pump less your flow is less thus less FL. What you didnt state is that if you EP stays the same and you have more FL than you thought (25-psi) your nozzle is not getting the pressure you thought either.

    I simply gave an example of a certain nozzle that when not supplied properly can lead to a dramatic flow drop that people should be aware of. I think its great that you have selected nozzles that do not have that problem. Great Work!

    I think however I found the error in my post that lead to your attack of my post.

    You stated:
    "We have all the stuff you mention on each and every rig figured to lays to 9000 feet. It is from that that we put together our rules of thumb"

    I'm sorry Larry. Your "Rule of Thumb" is based on MEASURED resulst based on what I read in your post. My modern day meaning of rule of thumb was different than yours.

    Now that I understand your rule of thumb is based on measured results I agree that for your engine, your hose, your nozzles, your "Rule of Thumb" works great....FOR YOU

    I'm curious Larry, why is it when other people post things that conflict with your ideas you reamain silent yet when I post, you go to great lengths to attack me and my ideas?

    You know that Numby's post was promoting the same thing as I yet your silent. You know that Ward Watson's numbers do not support your idea yet you are silent.

    Your last paragraph in your post implies to me that you know there are numerous problems out there yet we shouldn't try to fix them. I simply disagree with you, and I have that right!

    I have never implied that any type of class action suite should be raised. I simply do my best to teach people ways to limit there exposure form a potential legal issue.

    If you think this will only happen when hell freezes over then fine. You are entitled to you opinioin.

    Is your problem with me that fact that we will never advertise in your magazine for reasons your well aware of? I havent noticed Elkhart or Akron advertising in your magazine either.

    I hope that one day you will have the opportunity to talk with people that know me and know what I teach or better yet, sit in on a class. You will find that contrary to what you have been told from our competitors, I do know what I'm doing.

    I wish the best to you Larry and hope that in the future we can one day work towards the common good of the fire service. Such anomosity simply clouds the important issues that should be discussed.

    Take care and Stay Safe!


    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  17. #17
    LHS'
    Firehouse.com Guest

    Post

    Gee, why to I reply to you? You mention my name, or what I said in a post. So I'm not suppose to reply. We use Mercedes Textile hose.

    ///Maybe I missed somehting but I normally add NP to my total EP. ////

    I believe EP equals NP plus FL. So why do you add NP a second time?

    ///If my hose is eating up 25-psi more FL than I thought, then my nozzle MAY not be getting that extra 25-psi due to FL. ///

    You hammer me one second with threats of going to court if you overpump a line 24 psi like my rule of thumb suggested, because I'll be missing 25 psi nozzle pressure.

    Let's do the math, let's add the 24 psi additional EP:

    Automatic tip NP still 100 psi, flow instead of 250 gpm will be 281 gpm. The fire won't care, the judge won't care, the friction loss will now be 75 psi not 59, who cares? What difference does it make? Nozzle reaction is 16 pounds higher, I'll simply not open the nozzle all the way and never know it. Still no NP drop to due FL.

    Lower flow automatic???: 125 gpm automatic would need an NP of 350 psi flows 230 gpm. Np would need to be 470 psi. The flow would go up a tad the FL would go up a tad. Still no loss of NP.

    Fixed flow nozzle: 100 psi at 250 gpm will now flow 268 gpm at 115 psi NP and the friction loss will increase to 68 psi per length. Still no NP drop.

    Smoothbore: 15/16 tip 100 psi 250 gpm, The EP would jump to 110 psi, the friction loss to 70 and the flow would go crazy to 267 gpm and nozzle reaction would increase 15 pounds. Still no NP drop.

    Open butt: 14.5 psi NP flows 230 gpm with an EP of 117 psi and FL of 51 add 24 psi to the EP now it flows 254 gpm with FL of 61 and NP of 18. Still no NP drop.


    I wrote ... gosh I'm off by 24 psi, so what?

    Then you responded, ///Well I think a 24 psi mistake could lead to a real problem if it ends up that your nozzle is getting 25-psi less than needed. ///

    It doesn't work that way,

    ///What you didnt state is that if you EP stays the same and you have more FL than you thought (25-psi) your nozzle is not getting the pressure you thought either. ///

    OK EP stays the same 220 psi IT IS IMPOSSIBLE to have more FL unless you're changing hose diameter on me or the length of the line...UL says and you said I was under pumping my lines by 24 psi. SO PLEASE TELL US HOW THE FL INCREASES!!!!

    Why do I bother responding to you? Because you post crap like the above.

    ///I simply gave an example of a certain nozzle that when not supplied properly can lead to a dramatic flow drop that people should be aware of. I think its great that you have selected nozzles that do not have that problem. ///

    So, which nozzles are causing all these problems? Do they meet NFPA standards at the time of manufacture? Do they perform as advertised? How often do they need to be maintained? Every nozzle they make does this or just a few or a certain year or model? Come on man speak up, don't hide it. What will the judge say?

    Back to the tipic at hand, One more rule of thumb, with our hose that is dead on, always at any and every flow.

    4 times 2 1/2" FL is the FL for the 1 3/4" hose.

    4 inch hose gpm in hundreds is the FL per 100 feet times 2. 4 hundred gpm times 2 is 8 psi FL, 6oo is 12 psi, 1000 gpm is 20 psi.

    2 1/2" rule of thumb. Number each finger 1 through 10/ Left hand little finger say is 1 or 100 gpm, next finger is 2 or 200 gpm, etc.

    The knuckle below each finger starting left to right is numbered by counting in odd number fashion 3, 5, 7, 9, 11, 13, etc.

    Multiply the first finguer by the knuckle of 3 equals FL of 3 psi per 100 feet of 2 1/2 inch hose flowing 100 gpm. 2 times 5 is 10 psi fir 200 gpm, 300 gpm 3 times 7 is 21 psi, etc. Not exacly rule of thumb but if you calculate the thumb as 500 gpm the FL is 55 psi the other at 1000 gpm is 210 psi.

  18. #18
    KEA
    Firehouse.com Guest

    Post

    LHS:

    LARRY my original post was clear, and had measured results to support my opinion.

    I will not respond to your twists of the intent of my post nor will I be silent on matters that I feel are important.

    If you disagree so be it, If you dont like what I say, so be it. You cannot disprove the facts of my original post. A rule of thumb can and does get people in trouble. Your so called rule of thumb was not what most would call a rule of thumb considering it was bassed on measured resulst.

    "You hammer me one second with threat of going to court if you overpump a line 24 psi like my rule of thumb suggested"

    Great twist Larry! Go back and get it right Larry. MY post dealt with the fact one test reflected the pump pressure would have been off 45-psi, on the low side. Your the one who mentioned that your own theory was off by 24-psi and you stated "so what".

    Why would you imply that I am hammering YOU with threats? I'm not threatening any one.

    I never once suggested that overpumping was BAD, I simply pointed out that the rule of thumb you suggest would not work for the hose that was tested. Nothing MORE!

    I apprecieate your trying to tear me down with the use of automatic nozzle theory Larry. The fact remains, your rule of thumb did not work for the brand hose outlined and one of those tests was with an automatic nozzle. The point was to encuourage people to FLOW TEST and to build a chart....JUST LIKE YOU DID LARRY!

    You simply blow off the facts by questioning why a department uses a particular size hose. What they use is what they use! Your rule of thumb would not apply to that hose! Nothing more!

    Why is this turning into a nozzle discussion Larry? I am not permitted to mention nozzle brands on this forum as you are so well aware. However since you are so knowledgable surly you know what nozzles I'm speeking of. I will say again, considering your trying to twist what I said, it is not a nozzle problem! Your attempt to imply that it is by twisting what I said is not appreciated! This is a pumping problem and unfortunalty is masked by certain types of nozzles.

    "What will the judge say?"
    How would I know Larry? Why such an attack on the subject of legal issues when the post was simply attempting to help people limit their exposure to possible action.

    What does it take to have a civil conversation with you. All attempts seam futal.

    I truely wish you well and again hope that one day your obvious anomosity towards me and our company can be set aside for the betterment of the fire service.

    Stay safe and thanks for you posts.



    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  19. #19
    LHS'
    Firehouse.com Guest

    Cool

    ///A rule of thumb can and does get people in trouble.///

    Well, get on the horn and get IFSTA to quit posting them.

    ///I simply pointed out that the rule of thumb you suggest would not work for the hose that was tested.//

    Well here is one that will work for them

    2 times EP equals flow for all those departments using 100 foot attack lines out there. It is a shame you don’t use 50 foot or 20 foot lines you might get 1000 gpm at low pump pressures.

    Oh well, I guess these mystery nozzles you are always putting down to build your product up will have to go unnamed. Secrets I guess.

  20. #20
    EPFD-AL
    Firehouse.com Guest

    Post

    Here's my question: If I started work at 1800 HRS one hot and humid July night and after humping hose and pulling ceilings at four or five fires does anybody REALLY think I'm going to care about 24 GPM or 24 PSI?

  21. #21
    P.P.
    Firehouse.com Guest

    Post

    LHS,

    Here is the data from the Elkhart book on thier SM series nozzles (Automatics).

    SM-20 100-PSI NP = 212-GPM
    SM-20 75-PSI NP = 73-GPM

    SM-30 100-PSI NP = 300-GPM
    SM-30 75-PSI NP = 112-GPM

    SM-100 100-PSI NP = 1000-GPM
    SM-100 80-PSI NP = 200-GPM

    It is quite apparent that being off by 25-psi can cause a problem and your right the fire won't notice a difference in these flows, but the firefighters I think would.

    I to am a nozzle salesman, and I sell most brands.

    I would appreciate if you would not twist my post as you have with the posts from KEA.

    Stay Safe!

    P.P.

  22. #22
    KEA
    Firehouse.com Guest

    Post

    Thanks Larry, but it wont work.
    I have not put down any product nor have I even mentioned anything about our product.

    Again, your misinformed. Did you miss my post regarding Elkhart nozzles in the past? I clearly endorse and promote combination nozzles contrary to what you think.

    I believe that all nozzles are simply a tool in the tool box to be used by the person that feels its the tool for the job at hand. NOTHING MORE! I'm confident they are smart enough to pick the right tool without being told which product they should use.

    I appreciate PP pointing out some information that clearly supports why I promote building pump charts.

    A rule of thumb that is off 45-psi like I stated in my first post CAN lead to 25-psi off at the nozzle depending on flow and length.

    Looking at the post of PP you can now see that 25-psi off at the nozzle can mean as much as 190% less flow for the SM-20, 167% less flow for the SM-30 and 400%less flow for the SM-100.

    Before you start Larry...Read my post above. This is not a nozzle problem as you have attempted to claim I have stated. This is a pumping problem.

    I commend Elkhart for being the only one I know of that published the excact flows for their nozzles when underpressureized.

    "secrets I guess"

    If we had any secrets to keep why would we be the first Nozzle company to make it mandatory for our distributors and reps to utilize UL listed flowmeters Larry? We have nothing to hide even though you continue to insinuate otherwise.

    I'm done I will no longer respond to LHS on this thread.

    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  23. #23
    FyredUp
    Firehouse.com Guest

    Post

    bfd1071,

    For preconnects, test them with a flowmeter and mark the gauges for the flows you want.

    For made up lines, test a specific length, say 100 feet, at sepcific flows, again with a flow meter, and then make up a pump chart.

    Obviuosly the preconnects will have to be checked for each rig due to possible pump piping differences. The made up lines could be done once if the hose used is the same on all the different rigs in your department.

    Rules of thumb are great assuming that all things are equal, unfortunately with today's hose that rarely is true. Each manufacturer sells 1 3/4" hose. Some is 1 3/4", some is actually near or over 2 inch. If flow meters and pressure gauges are used and pump charts developed there is no need to guestimate anything.

    Take care,

    Don

    These are my opinions, yours may differ. Have a nice day!!


  24. #24
    KEA
    Firehouse.com Guest

    Post

    For those who are interested, the following quote is from Angus. It can be found on there web sight:

    "Do not accept theoretical data. "

    Who to know better than the people who make it!

    :http://www.angusfire.com/Angus/HOW%20TO%20BUY%20FIRE%20HOSE.html

    If you disagree with my post, take it up with Angus. I'm simply the messanger.



    ------------------
    Kirk Allen
    First Strike Technologies, Inc

  25. #25
    LHS'
    Firehouse.com Guest

    Post

    It has been written in regards to pumping 24 psi TOO MUCH ,

    ///The second test using the proposed 1-psi per 1-gpm concept would give you an engine pressure of 160-psi....25-psi higher than needed to actually get the desired flow of 160-gpm.///

    then you wrote:

    \Well I think a 24 psi mistake could lead to a real problem if it ends up that your nozzle is getting 25-psi less than needed.//

    As you can plainly see, even an Elkhart nozzle will not lose 25 psi at the nozzle when you pump too much. No one is twisting you words, you said this ridiculous stuff not me.

    ///This is not a nozzle problem as you have attempted to claim I have stated.///

    then we read: ///that 25-psi off at the nozzle can mean as much as 190% less flow for the SM-20, 167% less flow for the SM-30 and 400%less flow for the SM-100.//


    Sounds like a nozzle issue, anyone else care to give their opinion?

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