Help on plumbing a spray rig!

Discussion in 'Pesticide & Herbicide Application' started by fireman1173005, Jan 17, 2009.

  1. fireman1173005

    fireman1173005 LawnSite Member
    Posts: 111

    OK I am trying to plumb a skid sprayer and am having trouble getting enough pressure. I have 1" supply line running from my tank to my pump and 1" line from my pump to my reel. I have a centrifugal pump so of course it isn't going to put out as much pressure as a roller pump. I am wondering if I should increase the size of my supple line coming into the pump to say 1 1/2" so I will make sure and bring in more water to my pump than hopefully I am putting out, I think I may be starving my pump. What do u guys think?

    Thanks,

    Brian:confused:
     
  2. ted putnam

    ted putnam LawnSite Platinum Member
    Posts: 4,539

    The supply to your hose reel does not generally need to be as large as the supply to your pump. Do you have a line on the discharge side of your pump set up as "bypass"? That is to say any excess(unused by the hose reel) goes back to the tank hopefully in the form of agitation.
     
  3. greendoctor

    greendoctor LawnSite Fanatic
    Posts: 9,052

    What kind of pump? If this is a water transfer pump, those are not made to generate any kind of pressure. The centrifugal pumps I have seen designated for spraying are good for at least 75 PSI and over 20 GPM. At that rate, you should be able to run a boom or Lesco gun. Check your bypass or agitation valve too. If that is set to dump it all before it goes into your reel, there is no pressure. Also important is the hose size on your reel. The pressure loss on hose smaller than 5/8" is tremendous when you are talking about lengths over 50'. My rig has the standard D30 coupled to a 6.5HP engine. Pressure at the end of 200' of 3/8" hose is not 550PSI, but I can go up a 25' tree.
     
  4. fireman1173005

    fireman1173005 LawnSite Member
    Posts: 111

    I do have a bypass line. Do you think that if I made my line going to my reel it would increase my pressure?
     
  5. fireman1173005

    fireman1173005 LawnSite Member
    Posts: 111

    Yes it is a transfer pump. I didn't realize that they were less pressure that those for spraying. It was given to me so I can't complain. I can get it to put out about 40 psi, but that is wide open. Would I be better off switching to a roller pump at this point? I can use the same engine and buy a roller pump for about $100.

    Brian
     
  6. greendoctor

    greendoctor LawnSite Fanatic
    Posts: 9,052

    Yes, a roller pump would be more suited for your purposes. I cannot use roller pumps because what I run through my rig would eat the rollers in no time. You are ok if all you are going to spray is weed control and clear solution fertilizers. I spray too many fungicides and other chemicals that form a gritty suspension.
     
  7. fireman1173005

    fireman1173005 LawnSite Member
    Posts: 111

    Would a 3.5hp motor work ok for a roller pump? Most skids that I see for sale have 5 to 5 1/2 hp motors on them.
     
  8. greendoctor

    greendoctor LawnSite Fanatic
    Posts: 9,052

  9. fireman1173005

    fireman1173005 LawnSite Member
    Posts: 111

    thanks for all your help, and the link!!!
     
  10. RAlmaroad

    RAlmaroad LawnSite Silver Member
    from SC
    Posts: 2,182

    If you do change to a roller pump, make sure that you have an appropriate reduction (6:1 commonly) from the engine to the roller pump. I use the ones that are powered by the tractor PTO. Too high of a RPM will destroy the rollers quickly. Check that by-pass that it is not too far open as Greendoctor mentioned first.
     
    Last edited: Jan 17, 2009

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