1. #1
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    Question Hard Suction inquiries

    We need 20 Ft. of hard suction for our recently purchased used pumper (1500 GPM single stage). Can we flow 1500 GPM through a 5 inch hard line or will we need a 6 inch? How much could we flow out of a 5 inch line drafting out of a fol-da-tank (assume very little lift)? We are water challenged but could keep a tank full for 20-30 minutes or so.
    I realize I need 6 inch for testing but am looking at 5 inch because of budget limitations.

    Do we need a check valve in the strainer or will it generally hold its prime sitting if it passes it's static test?

    A couple small technical questions here for the engineers in the crowd, thanks in advance.

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    5" is rated for use on 1000 GPM at draft. If it is good condition it will probably allow you to deliver more but probably not 1500 GPM.
    If the pump is operating, even at idle, it should hold the draft.

    If you disengage the pump, you will lose the prime without a check valve. We only use check valves on our portable pumps.


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    What is the cost difference between 5" & 6"? You could make up the difference by dropping another suction line into the tank (a 2-1/2" if you carry them), but how would that effect operations? When it comes to getting water into the pump, go big.

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    Just a thought, but if you are questioning the purchase of 5 inch HT as compared to 6 in HT why would you have purchase a 1500 GPM pumper in the first place. There is not a great deal of price difference to start with in the 2 sizes and for the minimal cost you are getting what is needed to flow the 1500 gpm and as for the check valve we also only use it on portable pumps.

    Your statement as being water challenged should have answered your question!


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    To get your rated flow (1500gpm) you will need 6" hard suction line if you use only one line. Another thing to look closely at is the suction strainer you plan to use, I have seen some low level strainers used in fold-a-tank operations that don't have enough holes to equal the same cross section of 6" hard line being used. This situation will limit your flow rate the same as a smaller hard line. We run a 2250gpm pump that requires 2 6" hard suction lines to attain the rated flow, not practical for our tanker/fold-a-tank ops but really gets it done from a natural body of water. As far as the lift being only a few feet as opposed to the 10' lift used for testing, you may be able to deliver a couple of hundred gpm more than your rating. Of course there are always several factors in play that can affect drafting operations. Good luck and like someone already said, find some way to go big it will be well worth it!

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    1) You test 1500gpm pumps with 6". Doesn't mean 5" wouldn't do it if you have a strong pump. One of our trucks does 1400gpm through 30' 6" suction and 30' 6" piping plus valves. I'm gonna go out on a limb and say 5" for 20' would do as well if not better. But as your pump gets older, things loosen up doing the full 1500gpm will get tougher and tougher.

    2) Brass is more expensive than hose.
    Get prices for 2 -- 10' 5" lengths, and compare it to a single 20', 6" Kochek (lightweight) suction.
    I couldn't find a 20' piece online quickly, there's about a $60/length increase from 5" to 6"...my guess dropping two couplings will more than make up for it.

    A number of departments around me run with 1 -- 10' 6" and 1 -- 20' 6" length, the 20' is kept on the bottom and top suction hose shelves bending around at the back so the coupling & strainer are by the pump panel, with the 10' taking the middle shelf. We carry two 30' lengths on our water supply pumper.

    That may be the best compromise in performance & cost.
    I'm not sure if the single 20' length would be a real big drawback in portable tank operations though.
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    I'm not sure if the single 20' length would be a real big drawback in portable tank operations though.
    Um set the dam up ten more feet to the left or park the truck ten feet to the right.
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    Have I missed something? I don't know how you are going to connect the 5" suction to a 6" intake unless you buy an adaptor. The adaptor will be more than the difference in cost between 5" and 6".

    Check the Smeal site. I think they sell over stock equipment that they do not need for their new builds.

    I was once told by a pretty crafty pump operator don't walk away from the compartment with all the fittings until you know you have all the ones to make it work...


    The other thing you might do is ask your neighbor depts or a dealer in the area if someone upgraded to the clear light weight suction from the heavy black stuff. You might get a deal.

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    Don't use the front suction

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    LOL.............good one Artie !
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    Smile great input

    Thanks everyone for your excellent (productive) input. Top notch as always.

  12. #12
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    Originally posted by E229Lt
    Don't use the front suction
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    It will be dependent on the length of 5" hose, type of strainer at both ends of the hard suction hose, vertical lift, quality of the pump and piping to maintain a negative pressure, and the piping at pump suction (including valves, such as a butterfly valve).

    I ran a few calculations and found the following (I made some assumptions for the pump suction piping and included the strainer loss with the hard suction friction loss):

    10ft lift with 20 feet of 5" hose at 22"Hg (25 Feet):: 1,150 gpm
    10ft lift with 20 feet of 5" hose at 18"Hg (20 Feet):: 950 gpm

    Portable Tank:
    3 ft lift with 10 feet of 5" hose at 22" Hg (25 Feet):: 1,500 gpm
    3 ft lift with 10 feet of 5" hose at 18" Hg (20 Feet):: 1,350 gpm

    The numbers, as always, are not exact or highly refined. You really must conduct a test to see what flow rate your apparatus can achieve. If you do a test, I suggest doing two ways: (1) make sure every connection is tight - no leaks and (2) make sloppy connections. You will demonstrate to every one just how important it is to make the connections very tight.

    Also, a 1,500 gpm pump is a good choice, even if you do not have a 1,500 gpm source. A 1,000 gpm pumper is rated at 1,000 gpm at 150 psi (net pump pressure) while the 1,500 gpm pumper is rated at 1,050 gpm at 200 psi (net pump pressure). The 1,500 pumper will move the 1,000 gpm further. Also, you may find a 1,500 gpm source in the future.

    Good Luck

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