Pre set air on cd 74 high speed feeder

Discussion in 'Heidelberg Printing Presses' started by Jack liston, Sep 19, 2021.

  1. Jack liston

    Jack liston Senior Member

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    Location:
    Connecticut
    HELLO gentlemen am having issues with 50# offset stock on CD 74 keep getting double I have 40 years experience but am getting frustrated the separation air not working to low they are using ion blower to separate if I could reduce suction I would be better off seems I'm sucking through two sheets if increase fingers it misses ps the sucker can't be angled am using the light stock sucker.
     
  2. turbotom1052

    turbotom1052 Senior Member

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    Keep in mind Jack that your CD is engineered to flow big air numbers both blast and suction, to accommodate heavy substrates. You could always install a valve in the suction line to bleed off some of the vacuum, if your experience tells you that you need reduced suction.
     
  3. Steve F

    Steve F Member

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    Location:
    Scotland
    I've seen the same symptoms you're suffering from, especially the using the ionizers to help sheet separation!
    Ours was an air leak, but can be awkward to locate.

    Fortunately ours was right at the start of its journey...
    Feed air and delivery air come from the two large compressor/turbines, (one for each location) located in the AirStar cabinet near the feeder.
    If you open the doors to where the drier air supply, cooling and extraction system is (end cabinet) on the left hand side you'll see to the two hoses coming from the turbine side of the cabinet. With the compressor on, hopefully like us, you'll see the leak is there. If not you'll have to trace the feeder hose, under the walkway all the down to the feeder.

    Any leak will be obvious, as it's a tremendous amount of going through the hose.

    Hope this is of some help

    Steve
     
  4. Jack liston

    Jack liston Senior Member

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    Location:
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    Thanks for your help I appreciate it hope I can help someone else on the forum
     

  5. Steve F

    Steve F Member

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    Location:
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    Just to correct my post, I meant to say the two large compressors are at the delivery end of the press, not the feeder end.
    You'll have to remove the two cabinet covers/doors. The left hand one, with the large filter attached in it, houses the compressors, and the hoses will come out into the right hand cabinet, where hopefully the leak is.
     
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