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parallel vacs

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  • parallel vacs

    when using parallel vacs , is there a finite # of them you can use, say 2,3,4? what kind of strain do they put on themselves if there are too many? do they starv themselves of air if on a 1 1/2 inch hose? from what i understand they must be all the same size in individual lift to maintain balance,please explain.

  • #2
    vacuum boosters

    The most number of vacuums used in parallel I have seen in any unit is 4 vacuum motors.
    I do not believe you can put a stain on vacuum motors because the harder you work them the faster they spin. Test: note the rpm of a vacuum motor opened to the air and compare to a vacuum motor that is sealed off. The sealed off vacuum motor turns much faster because it is turning easier because of less air friction passing through the motor. Just make sure your vacuum hose is large enough to handle the cfm.
    The maximum cfm that can pass through 1.5" ID hose is 200 CFM.
    The maximum cfm that can pass through 2" ID hose is 400 CFM
    The maximum inches of lift will be the lesser of the components in parallel. For example: If I start of with a dual 3 stage series extractor (210" of lift @ max 100 cfm =21,000 vacuum units) and add a single 2 stage booster in parallels [mounted on vac lid/or down vacuum hose] (90" lift @ max 100 cfm =9,000 vacuum units) the new combined vacuum will be 90" lift @ 200 cfm = 18,000 vacuum units. You can see this will result in a loss of 3,000 vacuum units even though you doubled the cfm. The reason for the loss is the newer combined lower inches of lift. Vacuum booster need to equal the number of inches your machine has or offer a substantial increase in cfm. For example the Octavac booster offers a 127" lift @ 200 CFM (25,400 vacuum units) so a booster so even if you add it to any portable extractor you are going to take the cfm to 300 or 400 cfm depending on what you are starting off with. Lets us add the Octavac vac booster to the first machine mentioned above. New combined vacuum = 127" lift @ 300 cfm = 38,000 vacuum units. This is an increase of 17,000 vacuum units.
    Now lets add a vacuum booster to the above 1 st mentioned machine by adding another 3 stage vacuum to the exhaust of the second motor in series. First motor is 127" lift, this means the second motor is 127" X 70% = 88 inches of lift. The third motor would be 88 inches X 70% = 62 inches of lift. At sea level the maximun inches of lift 127 + 88 + 62 = 277" @ max 100 cfm = 27,700 vacuum units. Both inches of lift and cfm are equally important so always make sure that you are increasing you vacuum units before you add more vacuum. This is a 6,700 vacuum unit increase.


    • #3
      Vacuum boosting

      Hi Donald
      If you tested a 3-stage lamb amtek vacuum plastic body with a vacuum guage what inches of water lift would you expect to get.

      Kind Regards
      Last edited by Vacman3200; March 5, 2006, 03:20 AM. Reason: spelling


      • #4
        3 stage vacuum motor inches of lift (plastic body)

        I tested two different units today and one read 127" and one 130". These reading where taken at 1000 ft above sea level.