Why register? ...To Enhance Your Experience
Closed Thread
Page 1 of 2 12 LastLast
Results 1 to 20 of 22

Thread: How much GPM?

  1. #1
    Forum Member
    Join Date
    Jan 2008
    Location
    Utah
    Posts
    240

    Default How much GPM?

    Here's my question:

    I am pumping through 100ft of 5" supply line from a tender to an ARFF vehicle for resupply. Pumping @ 80 psi (max intake psi for ARFF vehicles), how can I determine how much GPMs I am giving that ARFF vehicle? Not necessarily looking for the answer, but how can I get that answer?

    Thanks


  2. #2
    MembersZone Subscriber
    Join Date
    Aug 2004
    Posts
    191

    Default

    Depends on what the GPM on the pump is. Example: if you have a 1,000 GPM pump. The pump is rated at that at 150 psi. so rough math 75 psi = 500 GPM. 5" holds a gallong a foot with pretty much no F/L. I think and don't quote me but I think 5" redlines at 1,000 GPM. I've never tested this so that's why I say don't quote me. Hope this helps.

  3. #3
    Forum Member FyredUp's Avatar
    Join Date
    Jul 1999
    Location
    Rural Wisconsin, Retired from the burbs of Milwaukee
    Posts
    9,683

    Default

    Pumping from what to what?

    P-26 to a P-23?

    Fill the tank on the tanker, have the crash truck pump itself dry. Make your connections and begin to fill the crash truck. If the tanker is bigger than the crash truck's tank the crash truck will have to discharge water so as not to overflow. When you empty the tank on the tanker divide the gallons in the tank by the time and voila...gpm's supplied.

    No formulas, no complicated math, just a little physical work and one division problem. Have fun.

  4. #4
    Forum Member FyredUp's Avatar
    Join Date
    Jul 1999
    Location
    Rural Wisconsin, Retired from the burbs of Milwaukee
    Posts
    9,683

    Default

    Quote Originally Posted by TRUCK61 View Post
    Depends on what the GPM on the pump is. Example: if you have a 1,000 GPM pump. The pump is rated at that at 150 psi. so rough math 75 psi = 500 GPM. 5" holds a gallong a foot with pretty much no F/L. I think and don't quote me but I think 5" redlines at 1,000 GPM. I've never tested this so that's why I say don't quote me. Hope this helps.
    Um, I am trying to find a polite way to say this...you are completely wrong on your 75 psi means half the pump capacity. Actually in many pumps less pressure means more flow, up to a point of course. Half the rated flow would come if we increased the pump pressure to 250 psi, 70% at 200 psi.

    Also, 5 inch hose will flow far more than 1000 gpm, depending on the length of the hose line. It is entirely possible to flow 2000 gpm through 5 inch hose.

  5. #5
    Forum Member
    Join Date
    Aug 2009
    Posts
    56

    Default GPM of 5" Hose

    FyredUp is correct! Flow tests done by my FD shows our 5" hose can handle 1600 GPM in a relay, usually 1000' between engines. In a short relay 5" can do 2000 GPM. If we have a hydrant that can supply more, we will connect to the hydrant with hard suction hose and can then supply a pair of 5" hoses in relay.

  6. #6
    MembersZone Subscriber
    Join Date
    Dec 2002
    Location
    Central NJ
    Posts
    1,214

    Default

    You take the difference between your discharge gauge and the intake gauge on the other rig. The number you get is the friction loss in the hose between both rigs. Look it up on a friction loss chart/table and see for a ballpark answer. Since you are using 5" hose at 100 feet, most charts go in 100' increments, so the answer (ballpark) should be easy to find.

    Another easy way to find out is do a timed test and see how long it takes to fill the tank from empty. Thats your GPM

  7. #7
    MembersZone Subscriber
    Join Date
    Aug 2004
    Posts
    191

    Default

    Fyred you are correct and I must have had a dyslexic moment so I apologize to everyone for giving out this misinformation. Thanks for setting this right.

  8. #8
    Forum Member FyredUp's Avatar
    Join Date
    Jul 1999
    Location
    Rural Wisconsin, Retired from the burbs of Milwaukee
    Posts
    9,683

    Default

    Quote Originally Posted by TRUCK61 View Post
    Fyred you are correct and I must have had a dyslexic moment so I apologize to everyone for giving out this misinformation. Thanks for setting this right.
    No problem Brother. That's why they never send us alone.

  9. #9
    Forum Member confire's Avatar
    Join Date
    Jan 2005
    Location
    Northern Indiana
    Posts
    328

    Default

    Pump capacity, hose size and PSI means squat if the tank to pump line is not of sufficient size to handle large flows. I would think most tankers (sorry just canít bring myself to say tender) would be hard pressed to deliver much over 800 GPM. Most likely less.

    With that said, I know absolutely nothing about ARFF ďtankersĒ so this may not be a concern. If itís a conventional fire service tanker the piping might be.

    I would like to know a little about how you operate? If you are pumping into a hose line (1000 feet) I assume the other ARFF is off the runway and has no pressurized hydrant available. If so, when the tanker runs dry what type of tanker would replace it? How would you setup a water supply?
    thanks

    EDIT: Sorry I misread the post. I thought it said 1000 feet and not 100 feet
    Last edited by confire; 08-29-2009 at 05:46 PM.

  10. #10
    Forum Member Rescue101's Avatar
    Join Date
    Jun 2001
    Location
    Bridgton,Me USA
    Posts
    8,162

    Default

    FL for 5" hose at AT CAPACITY is about 2-4 PSI per 100'. Therefore in the scenerio presented,you aren't losing squat,flow is limited by truck plumbing.If you know the tank size of the rig you're feeding,start with an empty tank and time it while you fill.When full,simple mathmatics will give you your fill rate.Simple,Yes? T.C.

  11. #11
    MembersZone Subscriber
    Join Date
    Dec 2002
    Location
    Central NJ
    Posts
    1,214

    Default

    Quote Originally Posted by Rescue101 View Post
    FL for 5" hose at AT CAPACITY is about 2-4 PSI per 100'. Therefore in the scenerio presented,you aren't losing squat,flow is limited by truck plumbing.If you know the tank size of the rig you're feeding,start with an empty tank and time it while you fill.When full,simple mathmatics will give you your fill rate.Simple,Yes? T.C.
    What capacity are you referring to?

  12. #12
    Forum Member Rescue101's Avatar
    Join Date
    Jun 2001
    Location
    Bridgton,Me USA
    Posts
    8,162

    Default

    According to my table on 5" it reaches "critical flow"(maximum flow without turbulation)at around 1200 GPM. In a 100' length you SHOULD be able to approach 2000GPM if Source and plumbing allow.If I REALLY wanted to know the fill rate on that vehicle,I would time how long it took to fill the tank and divide the tank capacity by the time and you have the flow rate(by minute).Different mfgs hose have different internal flow co-efficients so you need to try this on YOUR equipment to know what it is capable of flowing. A pitot guage can be helpful in finding out flow rates of your various equipment.And modern appliances are MUCH more efficient than the equipment of say ten years ago

  13. #13
    Forum Member FyredUp's Avatar
    Join Date
    Jul 1999
    Location
    Rural Wisconsin, Retired from the burbs of Milwaukee
    Posts
    9,683

    Default

    Quote Originally Posted by Rescue101 View Post
    If I REALLY wanted to know the fill rate on that vehicle,I would time how long it took to fill the tank and divide the tank capacity by the time and you have the flow rate(by minute).
    Isn't this basically what I said to do 2 days ago?

  14. #14
    Forum Member
    Join Date
    Sep 2009
    Location
    Nova Scotia, Canada
    Posts
    62

    Default Tankers

    Pump capacity, hose size and PSI means squat if the tank to pump line is not of sufficient size to handle large flows. I would think most tankers (sorry just canít bring myself to say tender) would be hard pressed to deliver much over 800 GPM. Most likely less.

    Not to rain on your parade I just thought this was a little funny seeing as almost all of the tankers in our fire dept. (63 Stations of which 45 are rural stations with typicly 1 tanker in every station) have at least 1050gpm pumps on them.

  15. #15
    Forum Member
    Join Date
    May 2001
    Location
    Greensboro, NC USA
    Posts
    1,294

    Default

    What's the tank size? Time how it takes to fill and find the flow rate that way.
    Quote Originally Posted by FyredUp View Post
    Um, I am trying to find a polite way to say this...you are completely wrong on your 75 psi means half the pump capacity.
    +1
    Quote Originally Posted by TRUCK61 View Post
    Fyred you are correct and I must have had a dyslexic moment so I apologize to everyone for giving out this misinformation. Thanks for setting this right.
    You might want to edit your original post to reflect that.
    The American people will never knowingly adopt Socialism. But under the name of 'liberalism' they will adopt every fragment of the Socialist program, until one day America will be a Socialist nation, without knowing how it happened. --Norman Mattoon Thomas, 6 time presidential candidate for the Socialist Party of America

  16. #16
    Forum Member confire's Avatar
    Join Date
    Jan 2005
    Location
    Northern Indiana
    Posts
    328

    Default

    Quote Originally Posted by MColley View Post

    Not to rain on your parade I just thought this was a little funny seeing as almost all of the tankers in our fire dept. (63 Stations of which 45 are rural stations with typicly 1 tanker in every station) have at least 1050gpm pumps on them.
    MColly my friend, you do know that just having a ď1050 gpm pumpĒ doesnít mean you can pump 1050GPM of water out of your tank donít you?

    BTW, donít sweat the rain on my parade, itís gonna be a flotilla

  17. #17
    MembersZone Subscriber
    Join Date
    Dec 2002
    Location
    Central NJ
    Posts
    1,214

    Default

    Quote Originally Posted by MColley View Post
    Pump capacity, hose size and PSI means squat if the tank to pump line is not of sufficient size to handle large flows. I would think most tankers (sorry just canít bring myself to say tender) would be hard pressed to deliver much over 800 GPM. Most likely less.

    Not to rain on your parade I just thought this was a little funny seeing as almost all of the tankers in our fire dept. (63 Stations of which 45 are rural stations with typicly 1 tanker in every station) have at least 1050gpm pumps on them.
    Not to rain on your parade, but unless you have twin 3" or a single 4" tank to pump line at least, your 1050 GPM pump don't do you alot of good getting that water out of the tank unless you are just dumping it.

  18. #18
    MembersZone Subscriber
    Join Date
    Sep 2006
    Location
    Kennett Square, PA USA
    Posts
    320

    Default

    OMG another first here on the Forum!!

  19. #19
    Forum Member
    Join Date
    Sep 2009
    Location
    Nova Scotia, Canada
    Posts
    62

    Default LOL Good points

    Quote Originally Posted by MG3610 View Post
    Not to rain on your parade, but unless you have twin 3" or a single 4" tank to pump line at least, your 1050 GPM pump don't do you alot of good getting that water out of the tank unless you are just dumping it.
    All very good points. I know that all of our trucks are capable of flowing what they are rated for out of the booster tanks. We have them speced out that way. Why you would put a pump in your truck and then not be able to feed it with your tank seems a little pointless. Kind of defeating the purpose of having the pump I would think.

    I do know that you can't always get wat your pump is rated for from your tank. We had problems with that in the past with "home made" trucks. But in our department we spec all of our tankers out to be dual purpose so we can use them as such and also we have to be able to off load all of our water through the pump as fast as we can with a dump valve should they fail. Again this stems from an issue arising in the past. I supose none of this helps with the origanl question though.

    All we would do here is put a ground monitor on your length of hose and Pito Gauge it.

  20. #20
    MembersZone Subscriber
    Join Date
    Dec 2002
    Location
    Central NJ
    Posts
    1,214

    Default

    Quote Originally Posted by MColley View Post
    All very good points. I know that all of our trucks are capable of flowing what they are rated for out of the booster tanks. We have them speced out that way. Why you would put a pump in your truck and then not be able to feed it with your tank seems a little pointless. Kind of defeating the purpose of having the pump I would think.

    I do know that you can't always get wat your pump is rated for from your tank. We had problems with that in the past with "home made" trucks. But in our department we spec all of our tankers out to be dual purpose so we can use them as such and also we have to be able to off load all of our water through the pump as fast as we can with a dump valve should they fail. Again this stems from an issue arising in the past. I supose none of this helps with the origanl question though.

    All we would do here is put a ground monitor on your length of hose and Pito Gauge it.
    Thats commendable, but you'd be surprised how many departments dont spec them for anything larger than the NFPA minimum TTP line.

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