Vacuum pressure on a Heidelberg Platen
We’re trying to get our Heidelberg dialed in and having a tough time with it. Our hypothesis is that the pump is creating too much vacuum - we put a gauge on it and measured 21 psi of vacuum. Online we found references to 7psi being the spec - but we can’t find anything official so two questions:
1) does anyone know for sure the vacuum pressure that it should run at
2) if it’s NOT 21psi - anyone have any theories for why it would be that high. We have checked and cleaned the dump valve and there’s no junk in it and it works fine on the bench.
Thanks in advance.
By “Heidelberg Platen” i assume you mean one of the “Windmills”? If so, can you open some of the unused pickup suckers to knock down the vacuum? BTW, do you mean 21 In/hg? Vacuum is not normally measured in PSI.
Don’t forget the clip on the sucker bar that covers a control hole to reduce the suction. Also paper pick up is not only suction, but table height, the amount of blow going into the top of the pile and last the sucker tilt which all combined makes for ¹a smooth running feed.