Tag: “Hg

Adjustable E-Vacs For All Kinds Of Vacuum Applications

Published on by Russ BowmanLeave a comment

EXAIR makes three different engineered compressed air products that are capable of pulling vacuum:

  • Air Amplifiers generate a very high vacuum flow (up to 25 times the compressed air flow rate) but not very much vacuum head. This makes them great for fumes, smoke, and airborne dust.
  • Line Vacs generate a moderate vacuum flow and head so they can easily convey bulk solids.
  • E-Vac Vacuum Generators generate a high vacuum head, but not a lot of vacuum flow. They’re commonly used with Vacuum Cups in pick-and-place applications, or a number of other applications where you measure the required vacuum in inches of mercury (the Air Amplifiers’ and Line Vacs’ vacuum heads are measured in inches of water.)

Our Adjustable E-Vac Vacuum Generators are the ones that typically fall into the “number of other applications” category above. While the In-Line E-Vacs are compact and reliably generate rated vacuum on demand, the Adjustable E-Vacs have some distinct advantages in certain cases:

Larger throat diameter. In-Line E-Vacs have a very tight throat, which generally doesn’t matter if they’re just hooked to Vacuum Cups that’ll be placed on a relatively clean surface. The wider throat of the Adjustable E-Vacs means that they can pass small debris from less-than-pristine surfaces that a Vacuum Cup might lift, or shavings that might fall into a work holding fixture on a machine tool. They can even pass liquids, so they’re sometimes used for small spill cleanup.

Adjustability. It’s right in the name, of course, but it IS a big deal. While you can regulate the supply pressure of almost any compressed air operated device to vary the performance level, you can thread the plug into, or out of, the body of an Adjustable E-Vac to literally put it in a whole new performance band. This is beneficial if you’re picking up, or holding down, pieces of different sizes, shapes, and weights. Just loosen the locking collar, make the adjustment, tighten it back up, and it’s ready for use.

With four distinct models to choose from, we can specify one with the vacuum performance and adjustability of range needed for your application. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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Vacuum Generators: Porous Vs. Non-Porous

Published on by Dave WoernerLeave a comment

I had customer call this week who was using an E-Vac model 800008H, an 8 SCFM Porous Vacuum Generator, to pull a vacuum on four vacuum cups.  He was trying to lift a part with the four vacuum cups placed on a clean metal portion of the part.  Unfortunately he was having a little trouble.  He had to lift the product very slowly because the part could easily be dislodged, if the part was bumped or came to an abrupt stop.

In-LineE-VacFamily
EXAIR’s family of In-Line E-Vac vacuum generators

The problem is a relatively simple one.  The customer choose a porous vacuum generator when he would be better served with a non-porous unit.  The vacuum cups are attaching to a non-porous surface, sheet metal, in a relatively clean environment.  The difference between porous and non-porous units is that  porous units has more vacuum flow available at a low vacuum level, where the non-porous vacuum generators have a higher level of vacuum, but less vacuum flow.  Because of the high vacuum flow, a porous unit is much better for lifting porous materials like cardboard, some particle boards, and fabrics.  The higher vacuum flow of porous vacuum generators helps maintain the vacuum when pulling upon materials which let a constant flow of air through. In the customer’s case, he was lifting a clean sheet of metal, a non-porous material, and needed a higher vacuum level as opposed to a higher vacuum flow. A higher vacuum level [more inches of mercury (Hg) of vacuum] would pull harder upon the metal and hold it tighter.

Let’s look at the customer’s example more closely.  An EXAIR model 800008, porous E Vac, will generate a maximum of 21 inches of mercury (“Hg).  A model 810008, non-porous E Vac, will generate 27  inches of mercury (“Hg).  Let say he was using a 900758 3 1/4” diameter round vacuum cup. If you look at the Vacuum Lift Chart, you see that the 900758 can lift 42.8 lbs. at 21 “HG, but it can lift 55.0 pounds at 27 “HG of mercury.  So in this application the customer can increase their lifting capacity by 28.5% by switching from a non-porous vacuum generator to a porous vacuum generator.

Dave Woerner
Application Engineer
davewoerner@exair.com
@EXAIR_DW