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Suction Hose Collapsing

Discussion in 'Chainsaws and Power Equipment' started by bobdog2o02, Aug 23, 2016.

  1. bobdog2o02

    bobdog2o02

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    Just like the title says, with the new 13 gpm pump on a machine that previously had a 8gpm pump, the suction hose is collapsing once it gets warm. It looks to be pretty flimsy chinese junk, not even any fiver reinforcing in the vinyl hose. What is a good replacement hose? stuff from Home depot or something at tractor supply? '
     
  2. Sconnie Burner

    Sconnie Burner

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    I would go to TSC and get a little larger diameter hose. I would think with the increased rate of flow you need to allow more voulume to travel through the hose.
     
  3. bobdog2o02

    bobdog2o02

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    I appreciate the input on that but the pump has a standard input fitting diameter.. . I'll be using the same size but something more rigid I think.
     
  4. redneckdan

    redneckdan

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    1.5" ID would be about the minimium I would feel comfortable with. You could be running sch 120 rigid with a pump that would suck the chrome off a trailer hitch but if you are running much over 6 fps inlet velocity you are in danger of cavitating the pump. Collapsing suction lines are nature's way of telling you to re-evaluate what the hell you are doing...
     
  5. Sconnie Burner

    Sconnie Burner

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    There should still be standard size fitting on the ends of a slightly larger hose.... What size I.D. or O.D. is it currently? I have a DHT w/ a 13 gpm pump with 1/2" hose, the tank is in the axle. You have to allow for the increased volume of fluid the pump needs. You are a little over one and half what you originally had. Think of it like a straw. Ever try to drink through one of the coffee stirrin straws/sticks as a kid? Those don't allow the volume we like now. So you need to upgrade to a Mc D's straw. Thats what I'm thinking needs to happen.

    What kind of splitter is it? Also look into the return hose. Is it allowing the fluid to flow back to the tank fast enough?
     
    Last edited: Aug 24, 2016
  6. bobdog2o02

    bobdog2o02

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    The problem only occurs when the old line gets hot. When it gets hot it gets soft because it's old and chitty... if it runs great until the melting point of the plastic is achieved why go bigger?
     
  7. JustWood

    JustWood Guest

    Get wire reinforced line.
    I was in need of some awhile back and I found it online . Ebay IIRC . I ended up getting it local.
     
  8. bobdog2o02

    bobdog2o02

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    Yup, went to a local hydraulic sales company and they had wire reinforced heavy duty hydraulic line, .95 cents/inch, wowzer. Fixed it right up.


    @ all who said go bigger. The flow is limited by the smallest orifice in the line.... if the smallest orifice is the pump inlet all that is achieved by going bigger is adding to the volume of fluid the system can hold.....
     
  9. Sconnie Burner

    Sconnie Burner

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    I just figured you needed more in the system to keep it cooler and to keep up with the pump, figuring thats what was causing the collapsing of the hose. Thats the only reason I recommended it. I missed the part where it was fine until warm/hot. Glad you found what you needed local!
     
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  10. Scotty Overkill

    Scotty Overkill Administrator

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    Beat me to it....
    If you have any nearby hydraulic line shops ( we have several here) they'd probably be able to get you what you need....
     
  11. redneckdan

    redneckdan

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    Kind of. The 'standard fitting' is close enough to the inlet port to be consider 'at the pump'. You want your supply hose velocity to be 2-4fpm to help avoid cavitation. The flow velocity jumps as it goes through the fitting but the important part is the 2-4gpm as the fluid goes through the bends in the hose.

    If by 'standard fitting' you mean a hose barb, then yer kinda limited in hose selection.
     
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  12. bobdog2o02

    bobdog2o02

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    Exactly.